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  • 1.
    Abrashev, Miroslav V.
    et al.
    Univ Sofia St Kliment Ohridski, Fac Phys, Sofia 1164, Bulgaria.
    Chernev, Petko
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Kubella, Paul
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Mohammadi, Mohammad Reza
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany;Univ Sistan & Baluchestan, Dept Phys, Zahedan 9816745845, Iran.
    Pasquini, Chiara
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Dau, Holger
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Zaharieva, Ivelina
    Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Origin of the heat-induced improvement of catalytic activity and stability of MnOx electrocatalysts for water oxidation2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 28, p. 17022-17036Article in journal (Refereed)
    Abstract [en]

    Catalysis of the oxygen evolution reaction (OER) by earth-abundant materials in the near-neutral pH regime is of great interest as it is the key reaction for non-fossil fuel production. To address the pertinent stability problems and insufficiently understood structure-activity relations, we investigate the influence of moderate annealing (100-300 degrees C for 20 min) for two types of electrodeposited Mn oxide films with contrasting properties. Upon annealing, the originally inactive and structurally well-ordered Oxide 1 of birnessite type became as OER active as the non-heated Oxide 2, which has a highly disordered atomic structure. Oxide 2 also improved its activity upon heating, but more important is the stability improvement: the operation time increased by about two orders of magnitude (in 0.1 M KPi at pH 7). Aiming at atomistic understanding, electrochemical methods including quantitative analysis of impedance spectra, X-ray spectroscopy (XANES and EXAFS), and adapted optical spectroscopies (infrared, UV-vis and Raman) identified structure-reactivity relations. Oxide structures featuring both di-mu-oxo bridged Mn ions and (close to) linear mono-mu-oxo Mn3+-O-Mn4+ connectivity seem to be a prerequisite for OER activity. The latter motif likely stabilizes Mn3+ ions at higher potentials and promotes electron/hole hopping, a feature related to electrical conductivity and reflected in the strongly accelerated rates of Mn oxidation and O-2 formation. Poor charge mobility, which may result from a low level of Mn3+ ions at high potentials, likely promotes inactivation after prolonged operation. Oxide structures related to the perovskite-like zeta-Mn2O3 were formed after the heating of Oxide 2 and could favour stabilization of Mn ions in oxidation states lower than +4. This rare phase was previously found only at high pressure (20 GPa) and temperature (1200 degrees C) and this is the first report where it was stable under ambient conditions.

  • 2.
    Anil, Athira
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering.
    White, Jai
    KTH Royal Inst Technol, Dept Chem Engn & Technol, Stockholm, Sweden.
    dos Santos, Egon Campos
    Tohoku Univ, Adv Inst Mat Res WPI AIMR, Sendai 9808577, Japan.
    Terekhina, Irina
    Stockholm Univ, Dept Mat & Environm Chem, Arrhenius Lab, S-10691 Stockholm, Sweden.
    Johnsson, Mats
    Stockholm Univ, Dept Mat & Environm Chem, Arrhenius Lab, S-10691 Stockholm, Sweden.
    Pettersson, Lars G. M.
    Stockholm Univ, Dept Phys, S-10691 Stockholm, Sweden.
    Cornell, Ann
    KTH Royal Inst Technol, Dept Chem Engn & Technol, Stockholm, Sweden.
    Salazar-Alvarez, German
    Uppsala Univ, Dept Mat Sci & Engn, Angstrom Lab, Box 35, S-75103 Uppsala, Sweden.
    Effect of pore mesostructure on the electrooxidation of glycerol on Pt mesoporous catalysts2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 31, p. 16570-16577Article in journal (Refereed)
    Abstract [en]

    Glycerol is a renewable chemical that has become widely available and inexpensive due to the increased production of biodiesel. Noble metal materials have shown to be effective catalysts for the production of hydrogen and value-added products through the electrooxidation of glycerol. In this work we develop three platinum systems with distinct pore mesostructures, e.g., hierarchical pores (HP), cubic pores (CP) and linear pores (LP); all with high electrochemically active surface area (ECSA). The ECSA-normalized GEOR catalytic activity of the systems follows HPC > LPC > CPC > commercial Pt/C. Regarding the oxidation products, we observe glyceric acid as the main three-carbon product (3C), with oxalic acids as the main two-carbon oxidation product. DFT-based theoretical calculations support the glyceraldehyde route going through tartronic acid towards oxalic acid and also help understanding why the dihydroxyacetone (DHA) route is active despite the absence of DHA amongst the observed oxidation products.

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  • 3.
    Araujo, Rafael B.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Banerjee, Amitava
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Panigrahi, Puspamitra
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Hindustan Univ, Ctr Clean Energy & Nanoconvergence, Chennai, Tamil Nadu, India.
    Yang, Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Araujo, C. Moyses
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden.
    Designing strategies to tune reduction potential of organic molecules for sustainable high capacity batteries application2017In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, no 9, p. 4430-4454Article in journal (Refereed)
    Abstract [en]

    Organic compounds evolve as a promising alternative to the currently used inorganic materials in rechargeable batteries due to their low-cost, environmentally friendliness and flexibility. One of the strategies to reach acceptable energy densities and to deal with the high solubility of known organic compounds is to combine small redox active molecules, acting as capacity carrying centres, with conducting polymers. Following this strategy, it is important to achieve redox matching between the chosen molecule and the polymer backbone. Here, a synergetic approach combining theory and experiment has been employed to investigate this strategy. The framework of density functional theory connected with the reaction field method has been applied to predict the formal potential of 137 molecules and identify promising candidates for the referent application. The effects of including different ring types, e.g. fused rings or bonded rings, heteroatoms, [small pi] bonds, as well as carboxyl groups on the formal potential, has been rationalized. Finally, we have identified a number of molecules with acceptable theoretical capacities that show redox matching with thiophene-based conducting polymers which, hence, are suggested as pendent groups for the development of conducting redox polymer based electrode materials.

  • 4.
    Araujo, Rafael B.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Islam, Muhammed Shafiqul
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Natl Univ Bangladesh, DSHE, Dhaka 1000, Bangladesh..
    Chakraborty, Sudip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, R.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden..
    Predicting electrochemical properties and ionic diffusion in Na2+2xMn2-x(SO4)(3): crafting a promising high voltage cathode material2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 2, p. 451-457Article in journal (Refereed)
    Abstract [en]

    Sodium ion batteries have emerged as a good alternative to lithium based systems due to their low cost of production. In this scenario, the search for higher voltage, sodium cathodes results in a new promising alluaudite structure Na2+2xMn2-x(SO4)(3). The structural, electronic and Na diffusion properties along with defects have been reported in this investigation within the framework of density functional theory. A band gap of 3.61 eV has been computed and the average deintercalation potential is determined to be 4.11 V vs. Na/Na+. A low concentration of anti-site defects is predicted due to their high formation energy. The biggest issue for the ionic diffusion in the Na2+2xMn2-x(SO4)(3) crystal structure is revealed to be the effect of Mn vacancies increasing the activation energy of Na+ ions that hop along the [001] equilibrium positions. This effect leads to activation energies of almost the same high values for the ionic hop through the [010] direction characterizing a 2D like ionic diffusion mechanism in this system.

  • 5.
    Araujo, Rafael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    N-2 adsorption on high-entropy alloy surfaces: unveiling the role of local environments2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 24, p. 12973-12983Article in journal (Refereed)
    Abstract [en]

    Developing highly active catalysts to electrochemically reduce N-2 to NH3 under ambient conditions is challenging but bears the promise of using ammonia as a potential energy vector in sustainable energy technology. One of the scientific challenges concerns the inertness of N-2 emanating from the highly stable triple bonds and the lack of dipole moments, making N-2 fixation on catalytic surfaces difficult. Another critical challenge is that electrons are more prone to reduce hydrogen than N-2 at the surface, forming a scaling relationship where the reduction ability of the catalyst most often benefits hydrogen reduction instead of nitrogen reduction. Here we show that high-entropy alloys (HEA) - a new class of catalysts with vast compositional and structural possibilities, can enhance N-2 fixation. More specifically, we investigate the role of the local environment in the first and second solvation shell of the adsorbing elements in the bond strength between the dinitrogen molecules and the HEA surfaces. Density functional theory using a Bayesian error estimation functional and vdW interactions is employed to clarify the properties dictating the local bonding. The results show that although the main property calibrating the N-2 bond strength is the d-band centers of the adsorbing elements, the value of the d-band centers of the adsorbing elements is further regulated by their local environment, mainly from the elements in the first solvation shell due to electron donor-acceptor interactions. Therefore, there exists a first solvation shell effect of the adsorbing elements on the bond strength between N-2 molecules and the surface of HEAs. The results show that apart from the direct active site, the indirect relation adds further modulation abilities where the local interactions with a breath of metallic elements could be used in HEAs to engineer specific surface environments. This is utilized here to form a strategy for delivering higher bond strength with the N-2 molecules, mitigating the fixation issue. The analysis is corroborated by correlation analysis of the properties affecting the interaction, thus forming a solid framework of the model, easily extendable to other chemical reactions and surface interaction problems.

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  • 6.
    Arvizu, Miguel A
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Qu, Hui-Ying
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Harbin Inst Technol, Sch Chem & Chem Engn, MIIT Key Lab Crit Mat Technol New Energy Convers, Harbin 150001, Heilongjiang, Peoples R China.
    Cindemir, Umut
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Qiu, Zhen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Rojas González, Edgar Alonso
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Granqvist, Claes Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Niklasson, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Electrochromic WO3 thin films attain unprecedented durability by potentiostatic pretreatment2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 6, p. 2908-2918Article in journal (Refereed)
    Abstract [en]

    Electrochromic windows and glass facades are able to impart energy efficiency jointly with indoor comfort and convenience. Long-term durability is essential for practical implementation of this technology and has recently attracted broad interest. Here we show that a simple potentiostatic pretreatment of sputterdeposited thin films of amorphous WO3-the most widely studied electrochromic material-can yield unprecedented durability for charge exchange and optical modulation under harsh electrochemical cycling in a Li-ion-conducting electrolyte and effectively evades harmful trapping of Li. The pretreatment consisted of applying a voltage of 6.0 V vs. Li/Li+ for several hours to a film backed by a transparent conducting In2O3: Sn layer. Associated compositional and structural modifications were probed by several techniques, and improved durability was associated with elemental intermixing at the WO3/ITO and ITO/glass boundaries as well as with carbonaceous solid-electrolyte interfacial layers on the WO3 films. Our work provides important new insights into long-term durability of ion-exchange-based devices.

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  • 7.
    Aung, Su Htike
    et al.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Shwebo Univ, Phys Dept, Shwebo 02261, Myanmar;Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zhao, Lichen
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland;Peking Univ, Dept Phys, State Key Lab Artificial Microstruct & Mesoscop P, Beijing 100871, Peoples R China.
    Nonomura, Kazuteru
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Oo, Than Zaw
    Univ Mandalay, Dept Phys, Mat Res Lab, Mandalay 05032, Myanmar.
    Zakeeruddin, Shaik M.
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Vlachopoulos, Nick
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Sloboda, Tamara
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Svanström, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Cappel, Ute B.
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Hagfeldt, Anders
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LSPM, Inst Chem Sci & Engn, Lab Photomol Sci, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Graetzel, Michael
    Swiss Fed Inst Technol Lausanne EPFL, EPFL SB ISIC LPI, Lab Photon & Interfaces, Inst Chem Sci & Engn, Chemin Alambics,Stn 6, CH-1015 Lausanne, Switzerland.
    Toward an alternative approach for the preparation of low-temperature titanium dioxide blocking underlayers for perovskite solar cells2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 17, p. 10729-10738Article in journal (Refereed)
    Abstract [en]

    The anodic electrodeposition method is investigated as an alternative technique for the preparation of a titanium oxide (TiO2) blocking underlayer (UL) for perovskite solar cells (PSCs). Extremely thin Ti-IV-based films are grown from aqueous acidic titanium(III) chloride in an electrochemical cell at room temperature. This precursor layer is converted to the UL (ED-UL), in a suitable state for PSC applications, by undertaking a sintering step at 450 degrees C for half an hour. PSCs with the composition of the light-absorbing material FA(0.85)MA(0.10)Cs(0.05)Pb(I0.87Br0.13)(3) (FA and MA denote the formamidinium and methylammonium cations, respectively) based on the ED-UL are compared with PSCs with the UL of a standard type prepared by the spray-pyrolysis method at 450 degrees C from titanium diisopropoxide bis(acetylacetonate) (SP-UL). We obtain power conversion efficiencies (PCEs) of over 20% for mesoscopic perovskite devices employing both ED-ULs and SP-ULs. Slightly higher fill factor values are observed for ED-UL-based devices. In addition, ED-ULs prepared by the same method have also been applied in planar PSCs, resulting in a PCE exceeding 17%, which is comparable to that for similar PSCs with an SP-UL. The preparation of ED-ULs with a lower sintering temperature, 150 degrees C, has also been examined. The efficiency of a planar PSC incorporating this underlayer was 14%. These results point out to the possibility of applying ED-ULs in flexible planar PSCs in the future.

  • 8.
    Banerjee, Amitava
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Araujo, Rafael B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden.
    Unveiling the thermodynamic and kinetic properties of NaxFe(SO4)2 (x = 0–2): toward a high-capacity and low-cost cathode material2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, p. 17960-17969Article in journal (Refereed)
    Abstract [en]

    The mineral eldfellite, NaFe(SO4)2, was recently proposed as an inexpensive candidate for the next generation of cathode application in Na-based batteries. Employing the density functional theory framework, we have investigated the phase stability, electrochemical properties and ionic diffusion of this eldfellite cathode material. We showed that the crystal structure undergoes a volume shrinkage of ≈8% upon full removal of Na ions with no imaginary frequencies at the Γ point of phonon dispersion. This evokes the stability of the host structure. According to this result, we proposed structural changes to get higher specific energy by inserting two Na ions per redox-active metal. Our calculations indicate NaV(SO4)2 as the best candidate with the capability of reversibly inserting two Na ions per redox center and producing an excellent specific energy. The main bottleneck for the application of eldfellite as a cathode is the high activation energies for the Na+ ion hop, which can reach values even higher than 1 eV for the charged state. This effect produces a low ionic insertion rate.

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  • 9.
    Banerjee, Amitava
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Chakraborty, Sudip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden..
    Bromination-induced stability enhancement with a multivalley optical response signature in guanidinium [C(NH2)(3)](+)-based hybrid perovskite solar cells2017In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, no 35, p. 18561-18568Article in journal (Refereed)
    Abstract [en]

    Guanidinium lead iodide (GAPbI(3)) has been synthesized experimentally, but stability remains an issue, which can be modulated by the insertion of bromine (Br) into the system. We have performed a systematic theoretical investigation to see how bromination can tune the stability of GAPbI(3). The optical properties were also determined, and we have found formation enthalpy-based stability in the perovskite systems, which are active in the visible and IR region even after bromine insertion and additionally more active in the IR range with the transition from GAPbI(3) to GAPbBr(3). The spin orbit coupling effect is considered throughout the band structure calculations. The ensemble of the primary and secondary gaps in the half and fully brominated hybrid perovskites leads to the phenomenon of a multipeak response in the optical spectra, which can be subsequently attributed as multivalley optical response behaviour. This multivalley optical behaviour enables the brominated guanidinium-based hybrid perovskites to exhibit broad light harvesting abilities, and this can be perceived as an idea for natural multi-junction solar cells.

  • 10.
    Banerjee, Amitava
    et al.
    Indian Inst Technol Jodhpur, Dept Met & Mat Engn, Jodhpur 342030, Rajasthan, India..
    Khossossi, Nabil
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Luo, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics. Indian Inst Technol Ropar, Dept Phys, Rupnagar 140001, Punjab, India..
    Promise and reality of organic electrodes from materials design and charge storage perspective2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 29, p. 15215-15234Article, review/survey (Refereed)
    Abstract [en]

    Organic electrode materials are becoming increasingly important as they reduce the C-footprint as well as the production cost of currently used and studied rechargeable batteries. With increasing demand for high-energy-density devices, over the past few decades, various innovative new materials based on the fundamental structure-property relationships and molecular design have been explored to enable high-capacity next-generation battery chemistries. One critical dimension that catalyzes this study is the building up of an in-depth understanding of the structure-property relationship and mechanism of alkali ion batteries. In this review, we present a critical overview of the progress in the technical feasibility of organic battery electrodes for use in long-term and large-scale electrical energy-storage devices based on the materials designing, working mechanisms, performance, and battery safety. Specifically, we discuss the underlying alkali ion storage mechanisms in specific organic batteries, which could provide the designing requirements to overcome the limitations of organic batteries. We also discuss the promising future research directions in the field of alkali ion organic batteries, especially multivalent organic batteries along with monovalent alkali ion organic batteries.

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  • 11.
    Baur, Christian
    et al.
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Källquist, Ida
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Chable, Johann
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Chang, Jin Hyun
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Johnsen, Rune E.
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Ruiz-Zepeda, Francisco
    Natl Inst Chem, Hajdrihova 19,POB 660, SI-1000 Ljubljana, Slovenia.
    Ateba Mba, Jean-Marcel
    Natl Inst Chem, Hajdrihova 19,POB 660, SI-1000 Ljubljana, Slovenia.
    Naylor, Andrew J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Garcia-Lastra, Juan Maria
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Vegge, Tejs
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Klein, Franziska
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Schür, Annika R.
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany.
    Norby, Poul
    Tech Univ Denmark, Dept Energy Convers & Storage, DK-2800 Lyngby, Denmark.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hahlin, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Fichtner, Maximilian
    Helmholtz Inst Ulm Electrochem Energy Storage, Helmholtzstr 11, D-89081 Ulm, Germany;Karlsruhe Inst Technol, Inst Nanotechnol, POB 3640, D-76021 Karlsruhe, Germany.
    Improved cycling stability in high-capacity Li-rich vanadium containing disordered rock salt oxyfluoride cathodes2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 37, p. 21244-21253Article in journal (Refereed)
    Abstract [en]

    Lithium-rich transition metal disordered rock salt (DRS) oxyfluorides have the potential to lessen one large bottleneck for lithium ion batteries by improving the cathode capacity. However, irreversible reactions at the electrode/electrolyte interface have so far led to fast capacity fading during electrochemical cycling. Here, we report the synthesis of two new Li-rich transition metal oxyfluorides Li2V0.5Ti0.5O2F and Li2V0.5Fe0.5O2F using the mechanochemical ball milling procedure. Both materials show substantially improved cycling stability compared to Li2VO2F. Rietveld refinements of synchrotron X-ray diffraction patterns reveal the DRS structure of the materials. Based on density functional theory (DFT) calculations, we demonstrate that substitution of V3+ with Ti3+ and Fe3+ favors disordering of the mixed metastable DRS oxyfluoride phase. Hard X-ray photoelectron spectroscopy shows that the substitution stabilizes the active material electrode particle surface and increases the reversibility of the V3+/V5+ redox couple. This work presents a strategy for stabilization of the DRS structure leading to improved electrochemical cyclability of the materials.

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  • 12.
    Bayrak Pehlivan, Ilknur
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Saguì, Nicole A.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering.
    Oscarsson, Johan
    Solibro Res AB, Vallvagen 5, S-75651 Uppsala, Sweden.
    Qiu, Zhen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics. KTH Royal Inst Technol, Dept Chem Engn, SE-10044 Stockholm, Sweden.
    Zwaygardt, Walter
    Forschungszentrum Julich, Inst Energy & Climate Res, IEK 14 Electrochem Proc Engn, D-52425 Julich, Germany.
    Lee, Minoh
    Forschungszentrum Julich, Inst Energy & Climate Res, IEK 14 Photovolta, D-52425 Julich, Germany.
    Mueller, Martin
    Forschungszentrum Juelich GmbH, Institute of Energy and Climate Research, IEK-14: Electrochemical Process Engineering, 52425 Juelich, Germany .
    Haas, Stefan
    Forschungszentrum Julich, Inst Energy & Climate Res, IEK 14 Photovolta, D-52425 Julich, Germany.
    Stolt, Lars
    Solibro Res AB, Vallvagen 5, S-75651 Uppsala, Sweden.
    Edoff, Marika
    Uppsala Univ, Solid State Elect, Dept Mat Sci & Engn, Box 534, S-75121 Uppsala, Sweden.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Scalable and thermally-integrated solar water-splitting modules using Ag-doped Cu(In,Ga)Se-2 and NiFe layered double hydroxide nanocatalysts2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 22, p. 12079-12091Article in journal (Refereed)
    Abstract [en]

    Photovoltaic (PV) electrolysis is an important and powerful technology for environmentally-friendly fuel production based on solar energy. By directly coupling solar cell materials to electrochemical systems to perform water electrolysis, solar energy can be converted into hydrogen fuel utilizing locally-generated heat and avoid losses from DC-DC convertors and power grid transmission. Although there have been significant contributions to the photoelectrochemical and PV-electrolysis field using isolated laboratory cells, the capacity to upscale and retain high levels of efficiency in larger modules remains a critical issue for widespread use and application. In this study, we develop thermally-integrated, solar-driven water-splitting device modules using AgCu(In,Ga)Se-2 (ACIGS) and an alkaline electrolyzer system with NiFe-layered double hydroxide (LDH) nanocatalysts with devices of 82-100 cm(2) area. The Ga-content in the ACIGS solar cells is tuned to achieve an optimal voltage for the catalyst system, and the average efficiencies and durability of the PV-electrolyzer were tested in up to seven-day indoor and 21 day outdoor operations. We achieved a solar-to-hydrogen (STH) module efficiency of 13.4% from gas volume measurements for the system with a six-cell CIGS-electrolyzer module with an active area of 82.3 cm(2) and a 17.27% PV module efficiency under 100 mW cm(-2) illumination, and thus 77% electricity-to-hydrogen efficiency at one full sun. Outdoor tests under mid-Europeen winter conditions exhibited an STH efficiency between 10 and 11% after the initial activation at the installation site in Julich, Germany, in December 2020, despite challenging outdoor-test weather conditions, including sub-zero temperatures.

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  • 13.
    Beydaghi, Hossein
    et al.
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy..
    Najafi, Leyla
    BeDimensional SpA, Via Albisola 121, I-16163 Genoa, Italy..
    Bellani, Sebastiano
    BeDimensional SpA, Via Albisola 121, I-16163 Genoa, Italy..
    Bagheri, Ahmad
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy..
    Martin-Garcia, Beatriz
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy..
    Salarizadeh, Parisa
    Vali E Asr Univ Rafsanjan, High Temp Fuel Cell Res Dept, Rafsanjan 7718897111, Iran..
    Hooshyari, Khadijeh
    Urmia Univ, Fac Chem, Dept Appl Chem, Orumiyeh 5756151818, Iran..
    Naderizadeh, Sara
    Ist Italiano Tecnol, Smart Mat, Via Morego 30, I-16163 Genoa, Italy..
    Serri, Michele
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy..
    Pasquale, Lea
    Ist Italiano Tecnol, Mat Characterizat Facil, Via Morego 30, I-16163 Genoa, Italy..
    Wu, Bing
    Univ Chem & Technol Prague, Dept Inorgan Chem, Tech 5, Prague 16628 6, Czech Republic..
    Oropesa Nunez, Reinier
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Solid State Physics.
    Sofer, Zdenek
    Univ Chem & Technol Prague, Dept Inorgan Chem, Tech 5, Prague 16628 6, Czech Republic..
    Pellegrini, Vittorio
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy.;BeDimensional SpA, Via Albisola 121, I-16163 Genoa, Italy..
    Bonaccorso, Francesco
    Ist Italiano Tecnol, Graphene Labs, Via Morego 30, I-16163 Genoa, Italy.;BeDimensional SpA, Via Albisola 121, I-16163 Genoa, Italy..
    Functionalized metallic transition metal dichalcogenide (TaS2) for nanocomposite membranes in direct methanol fuel cells2021In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 9, no 10, p. 6368-6381Article in journal (Refereed)
    Abstract [en]

    In this work, we designed a novel nanocomposite proton-exchange membrane (PEM) based on sulfonated poly(ether ether ketone) (SPEEK) and tantalum disulfide functionalized with terminal sulfonate groups (S-TaS2). The PEMs are prepared through a solution-casting method and exploited in direct methanol fuel cells (DMFCs). Two-dimensional S-TaS2 nanoflakes were prepared as a functional additive to produce the novel nanocomposite membrane for DMFCs due to their potential as a fuel barrier and an excellent proton conductor. To optimize the degree of sulfonation (DS) of SPEEK and the weight percentage (wt%) of S-TaS2 nanoflakes in PEMs, we used the central composite design of the response surface method. The optimum PEM was obtained for SPEEK DS of 1.9% and a weight fraction (wt%) of S-TaS2 nanoflakes of 70.2%. The optimized membrane shows a water uptake of 45.72%, a membrane swelling of 9.64%, a proton conductivity of 96.24 mS cm(-1), a methanol permeability of 2.66 x 10(-7) cm(2) s(-1), and a selectivity of 36.18 x 10(4) S s cm(-3). Moreover, SPEEK/S-TaS2 membranes show superior thermal and chemical stabilities compared to those of pristine SPEEK. The DMFC fabricated with the SPEEK/S-TaS2 membrane has reached the maximum power densities of 64.55 mW cm(-2) and 161.18 mW cm(-2) at 30 degrees C and 80 degrees C, respectively, which are similar to 78% higher than the values obtained with the pristine SPEEK membrane. Our results demonstrate that SPEEK/S-TaS2 membranes have a great potential for DMFC applications.

  • 14.
    Bhunia, Asamanjoy
    et al.
    Univ Ghent, Ctr Ordered Mat Organomet & Catalysis, Dept Inorgan & Phys Chem, Krijgslaan 281-S3, B-9000 Ghent, Belgium.;Univ Dusseldorf, Inst Anorgan Chem & Strukturchem, D-40204 Dusseldorf, Germany..
    Esquivel, Dolores
    Univ Ghent, Ctr Ordered Mat Organomet & Catalysis, Dept Inorgan & Phys Chem, Krijgslaan 281-S3, B-9000 Ghent, Belgium.;Univ Cordoba, Fac Sci, Dept Organ Chem, Nanochem & Fine Chem Res Inst IUIQFN, Campus Rabanales,Marie Curie Bldg,Ctra Nal 4, E-14071 Cordoba, Spain..
    Dey, Subarna
    Univ Dusseldorf, Inst Anorgan Chem & Strukturchem, D-40204 Dusseldorf, Germany..
    Fernandez-Teran, Ricardo
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Goto, Yasutomo
    Toyota Cent Res & Dev Labs Inc, Nagakute, Aichi 4801192, Japan..
    Inagaki, Shinji
    Toyota Cent Res & Dev Labs Inc, Nagakute, Aichi 4801192, Japan..
    Van der Voort, Pascal
    Univ Ghent, Ctr Ordered Mat Organomet & Catalysis, Dept Inorgan & Phys Chem, Krijgslaan 281-S3, B-9000 Ghent, Belgium..
    Janiak, Christoph
    Univ Dusseldorf, Inst Anorgan Chem & Strukturchem, D-40204 Dusseldorf, Germany..
    A photoluminescent covalent triazine framework: CO2 adsorption, light-driven hydrogen evolution and sensing of nitroaromatics2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 35, p. 13450-13457Article in journal (Refereed)
    Abstract [en]

    A highly photoluminescent (PL) porous covalent triazine-based framework (PCTF-8) is synthesized from tetra(4-cyanophenyl) ethylene by using trifluoromethanesulfonic acid as the catalyst at room temperature. Due to triazine units in the framework, the PCTF-8 exhibits excellent thermal stability (>400 degrees C). The Brunauer-Emmett-Teller (BET) specific surface area of PCTF-8 is 625 m(2) g(-1) which is lower than the one obtained from the synthesis under Lewis acid conditions (ZnCl2). At 1 bar and 273 K, the PCTF-8 adsorbs a significant amount of CO2 (56 cm(3) g(-1)) and CH4 (17 cm(3) g(-1)) which is highly comparable to nanoporous 1,3,5-triazine frameworks (NOP-1-6, 29-56 cm(3) g(-1)). This nitrogen rich framework exhibits good ideal selectivity (61 : 1 (85% N-2 : 15% CO2) at 273 K, 1 bar). Thus, it can be used as a promising candidate for potential applications in post-combustion CO2 capture and sequestration technologies. In addition, photoluminescence properties as well as the sensing behaviour towards nitroaromatics have been demonstrated. The fluorescence emission intensity of PCTF-8 is quenched by ca. 71% in the presence of 2,4,6-trinitrophenol (TNP). From time-resolved studies, a static quenching behaviour was found. This high photoluminescence property is used for hydrogen evolving organic photocatalysis from water in the presence of a sacrificial electron donor and a cocatalyst.

  • 15.
    Bielecki, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Parker, Stewart F.
    Ekanayake, Dharshani
    Rahman, Seikh M. H.
    Borjesson, Lars
    Karlsson, Maths
    Short-range structure of the brownmillerite-type oxide Ba2In2O5 and its hydrated proton-conducting form BaInO3H2014In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 40, p. 16915-16924Article in journal (Refereed)
    Abstract [en]

    The vibrational spectra and short-range structure of the brownmillerite-type oxide Ba2In2O6 and its hydrated form BaInO3H, are investigated by means of Raman, infrared, and inelastic neutron scattering spectroscopies together with density functional theory calculations. For Ba2In2O6, which may be described as an oxygen deficient perovskite structure with alternating layers of InO6 octahedra and InO4 tetrahedra, the results affirm a short-range structure of Icmm symmetry, which is characterized by random orientation of successive layers of InO4 tetrahedra. For the hydrated, proton conducting, form, BaInO3H, the results suggest that the short-range structure is more complicated than the P4/mbm symmetry that has been proposed previously on the basis of neutron diffraction, but rather suggest a proton configuration close to the lowest energy structure predicted by Martinez et al. [J.-R. Martinez, C. E. Moen, S. Stoelen, N. L. Allan, J. Solid State Chem., 180, 3388, (2007)]. An intense Raman active vibration at 150 cm(-1) is identified as a unique fingerprint of this proton configuration.

  • 16.
    Bielecki, Johan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics. Chalmers, Dept Appl Phys, SE-41296 Gothenburg, Sweden..
    Parker, Stewart F.
    Rutherford Appleton Lab, STFC, ISIS Facil, Didcot OX11 0QX, Oxon, England..
    Mazzei, Laura
    Chalmers, Dept Appl Phys, SE-41296 Gothenburg, Sweden..
    Börjesson, Lars
    Chalmers, Dept Appl Phys, SE-41296 Gothenburg, Sweden..
    Karlsson, Maths
    Chalmers, Dept Appl Phys, SE-41296 Gothenburg, Sweden..
    Structure and dehydration mechanism of the proton conducting oxide Ba2In2O5(H2O)(x)2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 4, p. 1224-1232Article in journal (Refereed)
    Abstract [en]

    The structure and dehydration mechanism of the proton conducting oxide Ba2In2O5(H2O)(x) are investigated by means of variable temperature (20-600 degrees C) Raman spectroscopy together with thermal gravimetric analysis and inelastic neutron scattering. At room temperature, Ba2In2O5(H2O)(x) is found to be fully hydrated (x = 1) and to have a perovskite-like structure, which dehydrates gradually with increasing temperature and at around 600 degrees C the material is essentially dehydrated (x approximate to 0.2). The dehydrated material exhibits a brownmillerite structure, which is featured by alternating layers of InO6 octahedra and InO4 tetrahedra. The transition from a perovskite-like to a brownmillerite-like structure upon increasing temperature occurs through the formation of an intermediate phase at ca. 370 degrees C, corresponding to a hydration degree of approximately 50%. The structure of the intermediate phase is similar to the structure of the dehydrated material, but with the difference that it exhibits a non-centrosymmetric distortion of the InO6 octahedra that is not present in the dehydrated material. The dehydration process upon heating is a two-stage mechanism; for temperatures below the hydrated-to-intermediate phase transition, dehydration is characterized by a homogenous release of protons over the entire oxide lattice, whereas above the transition a preferential desorption of protons originating in the nominally tetrahedral layers is observed. Furthermore, our spectroscopic results point towards the co-existence of two structural phases, which relate to the two lowest-energy proton configurations in the material. The relative contributions of the two proton configurations depend on how the sample is hydrated.

  • 17.
    Boota, Muhammad
    et al.
    Drexel Univ, AJ Drexel Nanomat Inst, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA..
    Jung, Euiyeon
    Drexel Univ, AJ Drexel Nanomat Inst, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Indian Inst Technol Ropar, Dept Phys, Rupnagar 140001, Punjab, India..
    Hussain, Tanveer
    Univ Western Australia, Sch Mol Sci, Perth, WA 6009, Australia.;Univ Queensland, Sch Chem Engn, St Lucia, Qld 4072, Australia..
    MXene binder stabilizes pseudocapacitance of conducting polymers2021In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 9, no 36, p. 20356-20361Article in journal (Refereed)
    Abstract [en]

    Conducting polymers (CPs) are by far the most studied organic materials for supercapacitors. Yet, their structural instability stemming from volumetric expansion/contraction during charge/discharge results in capacitance loss after moderate cycling that limits their applications. Here, we show that the remarkable cycling stability, capacitance, and rate performance can be achieved by replacing conventional electrode additives (carbon black or insulating polymer binder) with titanium carbide (Ti3C2Tx) MXene. Using polyaniline (PANI) as a model system, an addition of only 15 wt% of Ti3C2Tx MXene binder delivered remarkable capacitance retention of 96% after 10 000 cycles at 50 mV s(-1) and high-rate capability with a capacitance of 434 F g(-1). Using density functional theory (DFT) calculations, we show that, unlike insulating polymer binders, surface groups of MXene bond to PANI with a significantly high binding energy (up to -2.11 eV) via a charge transfer mechanism. This is one of the key mechanisms to achieve a high electrochemical performance of the CP-based electrodes when MXene is used as a binder. We expect that a similar approach can be used for stabilizing other organic electrode materials.

  • 18.
    Chang, Ribooga
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Svensson Grape, Erik
    Clairefond, Teva
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Tikhomirov, Evgenii
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Inge, A. Ken
    Cheung, Ocean
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Synthesis and characterization of sodium hafnium oxide (Na2HfO3) and its high-temperature CO2 sorption properties2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 14, p. 7617-7628Article in journal (Refereed)
    Abstract [en]

    The CO2 sorption properties of sodium hafnium oxide (Na2HfO3) were investigated in this study. Na2HfO3 was synthesized by solid-state synthesis using Na2CO3 and HfO2 as starting materials. The solid-state synthesized Na2HfO3 appeared structurally similar to other mixed metal oxides such as Na2ZrO3, but stacking disorder appeared to be common in Na2HfO3. The synthesis conditions, including the Na : Hf ratio (between 0.5 and 1.5 : 1), synthesis temperature, time and heating rate, were investigated to optimize CO2 sorption properties of Na2HfO3. The Na2HfO3 sorbent showed comparable CO2 uptake capacity, reaction rate and excellent cycling stability compared to other metal oxide sorbents. Na2HfO3 with Na : Hf = 1 : 1 and 1.25 : 1 showed the highest CO2 uptake among all Na2HfO3 samples obtained, with a CO2 uptake capacity of around 15 wt% (at 650–800 °C). The CO2 uptake rate of NHO-1 and NHO-1.25 was fast with over 80% of the equilibrium uptake reached within 250 s. Na2HfO3 remained stable even after 100 cycles with less than 3% difference in the CO2 uptake capacity between the 1st and 100th cycles. We performed kinetic analysis on the CO2 sorption data and found that the Avrami–Erofeev model fitted the kinetic data best among the kinetic models used. Apart from sorbent optimization, we showed that 3D-printing of Na2HfO3 : HfO2 mixtures can be used to produce structured Na2HfO3 sorbents with a slightly improved CO2 uptake rate and the same CO2 uptake capacity as the powder-based solid-state synthesized Na2HfO3 sorbent.

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  • 19.
    Chang, Ribooga
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Wu, Xianyue
    Nanyang Technol Univ, Sch Chem & Biomed Engn, 62 Nanyang Dr, Singapore 637459, Singapore.;Nanyang Environm Water Res Inst, Interdisciplinary Grad Programme, 1 Cleantech Loop, Singapore 637141, Singapore..
    Cheung, Ocean
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Liu, Wen
    Nanyang Technol Univ, Sch Chem & Biomed Engn, 62 Nanyang Dr, Singapore 637459, Singapore..
    Synthetic solid oxide sorbents for CO2 capture: state-of-the art and future perspectives2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 4, p. 1682-1705Article, review/survey (Refereed)
    Abstract [en]

    Carbon capture is an important and effective approach to control the emission of CO2 from point sources such as fossil fuel power plants, industrial furnaces and cement plants into the atmosphere. For an efficient CO2 capture operation, many aspects of the CO2 capture steps need to be carefully considered. Currently the most mature CO2 capture technology is liquid amine scrubbing. Alternatively, solid sorbents can be used to effectively capture CO2 while alleviating the disadvantages associated with liquid amine sorbents. In this review, we critically assess solid metal oxide CO2 sorbents, especially oxides of group 1 (Li, Na and K) and group 2 (Mg, Ca, Sr and Ba) metals, for capturing CO2 at moderate to high temperatures. In particular, we focus on the recent advances in developing synthetic metal oxide sorbents, and the correlation between the design, synthetic approaches and their cyclic CO2 capture performance, which are characterised by CO2 uptake capacity, rate of carbonation and cyclic stability. The state-of-the-art, challenges, opportunities and future research directions for these metal oxide sorbents are discussed. By devoting more research effort to address the issues identified, there can be great potential to utilise Group 1 and 2 metal oxides as cost-effective, highly efficient sorbents for CO2 capture in a variety of carbon capture applications.

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  • 20.
    Chen, Yu
    et al.
    Shanghai Univ, Shanghai, Peoples R China..
    Davies, Gemma-Louise
    UCL, London, England..
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Kotov, Nicholas
    Univ Michigan, Ann Arbor, MI USA..
    Introduction to 1D/2D materials for energy, medicine and devices2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 34, p. 17891-17891Article in journal (Other academic)
  • 21.
    Choudhury, Sneha
    et al.
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods Mat Dev, Albert Einstein Str 15, D-12489 Berlin, Germany;Free Univ Berlin, Inst Chem & Biochem, Fabeckstr 36a, D-14195 Berlin, Germany.
    Kiendl, Benjamin
    Univ Wurzburg, Inst Organ Chem, D-97074 Wurzburg, Germany.
    Ren, Jian
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods Mat Dev, Albert Einstein Str 15, D-12489 Berlin, Germany;Free Univ Berlin, Dept Phys, Arnimallee 14, D-14195 Berlin, Germany.
    Gao, Fang
    Fraunhofer Inst Appl Solid State Phys IAF, Tullastr 72, D-79108 Freiburg, Germany;Max Planck Inst Mikrostrukturphys, Weinberg 2, D-06120 Halle, Germany.
    Knittel, Peter
    Fraunhofer Inst Appl Solid State Phys IAF, Tullastr 72, D-79108 Freiburg, Germany.
    Nebel, Christoph
    Fraunhofer Inst Appl Solid State Phys IAF, Tullastr 72, D-79108 Freiburg, Germany.
    Venerosy, Amelie
    CEA, LIST, Diamond Sensors Lab, F-91191 Gif Sur Yvette, France.
    Girard, Hugues
    CEA, LIST, Diamond Sensors Lab, F-91191 Gif Sur Yvette, France.
    Arnault, Jean-Charles
    CEA, LIST, Diamond Sensors Lab, F-91191 Gif Sur Yvette, France.
    Krueger, Anke
    Univ Wurzburg, Inst Organ Chem, D-97074 Wurzburg, Germany.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Petit, Tristan
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods Mat Dev, Albert Einstein Str 15, D-12489 Berlin, Germany.
    Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 34, p. 16645-16654Article in journal (Refereed)
    Abstract [en]

    Diamond is a promising metal-free photocatalyst for nitrogen and carbon dioxide reduction in aqueous environment owing to the possibility of emitting highly reducing solvated electrons. However, the wide band gap of diamond necessitates the use of deep UV to trigger a photochemical reaction. Boron doping introduces acceptor levels within the band gap of diamonds, which may facilitate visible-light absorption through defect-based transitions. In this work, unoccupied electronic states from different boron-doped diamond materials, including single crystal, polycrystalline film, diamond foam, and nanodiamonds were probed by soft X-ray absorption spectroscopy at the carbon K edge. Supported by density functional theory calculations, we demonstrate that boron close to the surfaces of diamond crystallites induce acceptor levels in the band gap, which are dependent on the diamond morphology. Combining boron-doping with morphology engineering, this work thus demonstrates that electron acceptor states within the diamond band gap can be controlled.

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  • 22.
    Das, Biswanath
    et al.
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Toledo-Carrillo, Esteban A.
    KTH Royal Inst Technol, Dept Appl Phys, Hannes Alfvens Vag 12, S-11419 Stockholm, Sweden..
    Li, Guoqi
    ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China..
    Stahle, Jonas
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Thersleff, Thomas
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Chen, Jianhong
    Stockholm Univ, Dept Mat & Environm Chem, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Li, Lin
    ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China..
    Ye, Fei
    KTH Royal Inst Technol, Dept Appl Phys, Hannes Alfvens Vag 12, S-11419 Stockholm, Sweden..
    Slabon, Adam
    Univ Wuppertal, Inorgan Chem, Gaussstr 20, D-42119 Wuppertal, Germany..
    Gothelid, Mats
    KTH Royal Inst Technol, Mat & Nanophys, Hannes Alfvens Vag 12, S-11419 Stockholm, Sweden..
    Weng, Tsu-Chien
    ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 201210, Peoples R China..
    Yuwono, Jodie A.
    Univ New South Wales, Sch Chem Engn, Sydney 2052, Australia..
    Kumar, Priyank V.
    Univ New South Wales, Sch Chem Engn, Sydney 2052, Australia..
    Verho, Oscar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Drug Design and Discovery.
    Karkas, Markus D.
    KTH Royal Inst Technol, Dept Chem, SE-10044 Stockholm, Sweden..
    Dutta, Joydeep
    KTH Royal Inst Technol, Dept Appl Phys, Hannes Alfvens Vag 12, S-11419 Stockholm, Sweden..
    Akermark, Bjorn
    Stockholm Univ, Dept Organ Chem, Arrhenius Lab, Svante Arrhenius Vag 16C, S-10691 Stockholm, Sweden..
    Bifunctional and regenerable molecular electrode for water electrolysis at neutral pH2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 25, p. 13331-13340Article in journal (Refereed)
    Abstract [en]

    The instability of molecular electrodes under oxidative/reductive conditions and insufficient understanding of the metal oxide-based systems have slowed down the progress of H-2-based fuels. Efficient regeneration of the electrode's performance after prolonged use is another bottleneck of this research. This work represents the first example of a bifunctional and electrochemically regenerable molecular electrode which can be used for the unperturbed production of H-2 from water. Pyridyl linkers with flexible arms (-CH2-CH2-) on modified fluorine-doped carbon cloth (FCC) were used to anchor a highly active ruthenium electrocatalyst [Ru-II(mcbp)(H2O)(2)] (1) [mcbp(2-) = 2,6-bis(1-methyl-4-(carboxylate)benzimidazol-2-yl)pyridine]. The pyridine unit of the linker replaces one of the water molecules of 1, which resulted in RuPFCC (ruthenium electrocatalyst anchored on -CH2-CH2-pyridine modified FCC), a high-performing electrode for oxygen evolution reaction [OER, overpotential of similar to 215 mV] as well as hydrogen evolution reaction (HER, overpotential of similar to 330 mV) at pH 7. A current density of similar to 8 mA cm(-2) at 2.06 V (vs. RHE) and similar to-6 mA cm(-2) at -0.84 V (vs. RHE) with only 0.04 wt% loading of ruthenium was obtained. OER turnover of >7.4 x 10(3) at 1.81 V in 48 h and HER turnover of >3.6 x 10(3) at -0.79 V in 3 h were calculated. The activity of the OER anode after 48 h use could be electrochemically regenerated to similar to 98% of its original activity while it serves as a HE cathode (evolving hydrogen) for 8 h. This electrode design can also be used for developing ultra-stable molecular electrodes with exciting electrochemical regeneration features, for other proton-dependent electrochemical processes.

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  • 23.
    Duchon, Tomas
    et al.
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany;Charles Univ Prague, Fac Math & Phys, Dept Surface & Plasma Sci, Prague 18000, Czech Republic.
    Hackl, Johanna
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany.
    Mueller, David N.
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany.
    Kullgren, Jolla
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Du, Dou
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Senanayake, Sanjaya D.
    Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA.
    Mouls, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Lab Nacl Luz Sincrotron, BR-13083 Campinas, SP, Brazil.
    Gottlob, Daniel M.
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany.
    Khan, Muhammad I.
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany.
    Cramm, Stefan
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany.
    Veltruska, Katerina
    Charles Univ Prague, Fac Math & Phys, Dept Surface & Plasma Sci, Prague 18000, Czech Republic.
    Matolin, Vladimir
    Charles Univ Prague, Fac Math & Phys, Dept Surface & Plasma Sci, Prague 18000, Czech Republic.
    Nemsak, Slavomir
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany;Lawrence Berkeley Natl Lab, Adv Light Source, Berkeley, CA 94720 USA.
    Schneider, Claus M.
    Forschungszentrum Julich, Peter Grunberg Inst 6, D-52425 Julich, Germany;Univ Calif Davis, Dept Phys, Davis, CA 95616 USA.
    Establishing structure-sensitivity of ceria reducibility: real-time observations of surface hydrogen interactions2020In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 8, no 11, p. 5501-5507Article in journal (Refereed)
    Abstract [en]

    The first Layer of atoms on an oxide cataLyst provides the first sites for adsorption of reactants and the Last sites before products or oxygen are desorbed. We employ a unique combination of morphological, structural, and chemical analyses of a model ceria cataLyst with different surface terminations under an H2 environment to unequivocally establish the effect of the Last Layer of atoms on surface reduction. (111) and (100) terminated epitaxiaL isLands of ceria are simultaneously studied in situ allowing for a direct investigation of the structure reducibility relationship under identical conditions. Kinetic rate constants of Ce4+ to Ce3+ transformation and equilibrium concentrations are extracted for both surface terminations. Unlike the kinetic rate constants, which are practically the same for both types of isLands, more pronounced oxygen release, and overall higher reducibility were observed for (100) isLands compared to (111) ones. The findings are in agreement with coordination -Limited oxygen vacancy formation energies calculated by density functional theory. The results point out the important aspect of surface terminations in redox processes, with particular impact on the catalytic reactions of a variety of catalysts.

  • 24. Dwibedi, D.
    et al.
    Barros Neves de Araujo, Rafael
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Chakraborty, Sidip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Shanbogh, P. P.
    Sundaram, N. G.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Barpanda, P.
    Na2.44Mn1.79(SO4 )3: A new member of alluaudite family of insertion compounds for sodium ion batteries2015In: Journal of Materials Chemistry A, ISSN 2050-7488Article in journal (Other academic)
  • 25. Dwibedi, Debasmita
    et al.
    Araujo, Rafael B.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Chakraborty, Sudip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Shanbogh, Pradeep P.
    Sundaram, Nalini G.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Barpanda, Prabeer
    Na2.44Mn1.79(SO4)(3): a new member of the alluaudite family of insertion compounds for sodium ion batteries2015In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 36, p. 18564-18571Article in journal (Refereed)
    Abstract [en]

    Sodium-ion batteries have been extensively pursued as economic alternatives to lithium-ion batteries. Investigating the polyanion chemistry, alluaudite structured Na2Fe2II(SO4)(3) has been recently discovered as a 3.8 V positive electrode material (Barpanda et al., Nature Commun., 5: 4358, 2014). Registering the highest ever Fe-III/Fe-II redox potential (vs. Na/Na+) and formidable energy density, it has opened up a new polyanion family for sodium batteries. Exploring the alluaudite family, here we report isotypical Na2+2xMn2-xII(SO4)(3) (x = 0.22) as a novel high-voltage cathode material for the first time. Following low-temperature (ca. 350 degrees C) solid-state synthesis, the structure of this new alluaudite compound has been solved adopting a monoclinic framework (s.g. C2/c) showing antiferromagnetic ordering at 3.4 K. Synergising experimental and ab initio DFT investigation, Na2+2xMn2-xII(SO4)(3) has been found to be a potential high-voltage (ca. 4.4 V) cathode material for sodium batteries.

  • 26.
    Ebadi, Mahsa
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Marchiori, Cleber
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Araujo, Carlos Moyses
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Assessing structure and stability of polymer/lithium-metal interfaces from first-principles calculations2019In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 7, no 14, p. 8394-8404Article in journal (Refereed)
    Abstract [en]

    Solid polymer electrolytes (SPEs) are promising candidates for Li metal battery applications, but the interface between these two categories of materials has so far been studied only to a limited degree. A better understanding of interfacial phenomena, primarily polymer degradation, is essential for improving battery performance. The aim of this study is to get insights into atomistic surface interaction and the early stages of solid electrolyte interphase formation between ionically conductive SPE host polymers and the Li metal electrode. A range of SPE candidates are studied, representative of major host material classes: polyethers, polyalcohols, polyesters, polycarbonates, polyamines and polynitriles. Density functional theory (DFT) calculations are carried out to study the stability and the electronic structure of such polymer/Li interfaces. The adsorption energies indicated a stronger adhesion to Li metal of polymers with ester/carbonate and nitrile functional groups. Together with a higher charge redistribution, a higher reactivity of these polymers is predicted as compared to the other electrolyte hosts. Products such as alkoxides and CO are obtained from the degradation of ester- and carbonate-based polymers by AIMD simulations, in agreement with experimental studies. Analogous to low-molecular-weight organic carbonates, decomposition pathways through C-carbonyl-O-ethereal and C-ethereal-O-ethereal bond cleavage can be assumed, with carbonate-containing fragments being thermodynamically favorable.

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  • 27.
    Etman, Ahmed S.
    et al.
    Stockholms Universitet.
    Asfaw, Habtom D.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Yuan, Ning
    Stockholm University and SLU.
    Li, Jian
    Peking University, China.
    Zhou, Zhengyang
    Peking University.
    Peng, Fei
    Stockholm University.
    Persson, Ingmar
    Swedish University of Agricultural Sciences.
    Zou, Xiaodong
    Stockholm University.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Sun, Junliang
    Stockholm University and Peking University.
    A one-step water based strategy for synthesizing hydrated vanadium pentoxide nanosheets from VO2(B) as free-standing electrodes for lithium battery applications2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 46, p. 17988-18001Article in journal (Refereed)
    Abstract [en]

    The synthesis of two dimensional (2D) materials from transition metal oxides, chalcogenides, and carbides mostly involve multiple exfoliation steps in which hazardous solvents and reagents are used. In this study, hydrated vanadium pentoxide (V2O5[middle dot]nH2O) nanosheets with a thickness of a few nanometers were prepared via a facile environmentally friendly water based exfoliation technique. The exfoliation process involved refluxing the precursor, vanadium dioxide (VO2(B)), in water for a few days at 60 [degree]C. The proposed exfoliation mechanism is based on the intercalation/insertion of water molecules into the VO2(B) crystals and the subsequent cleavage of the covalent bonds holding the layers of VO2(B) together. The thermal and chemical analyses showed that the approximate chemical composition of the nanosheets is H0.4V2O5[middle dot]0.55H2O, and the percentage of VV content to that of VIV in the nanosheets is about 80(3)% to 20(3)%. The exfoliated aqueous suspension of the V2O5[middle dot]0.55H2O nanosheets was successfully deposited onto multi-walled carbon nanotube (MW-CNT) paper to form free-standing electrodes with a thickness of the V2O5[middle dot]0.55H2O layer ranging between 45 and 4 [small mu ]m. A series of electrochemical tests were conducted on the electrodes to determine the cyclability and rate capability of lithium insertion into V2O5[middle dot]0.55H2O nanosheets. The electrodes with the thinnest active material coating ([similar]4 [small mu ]m) delivered gravimetric capacities of up to 480 and 280 mA h g-1 when cycled at current densities of 10 and 200 mA g-1, respectively.

  • 28.
    Gao, Jiajia
    et al.
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Yang, Wenxing
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    El-Zohry, Ahmed M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Prajapati, Govind Kumar
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Fang, Yuan
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Dai, Jing
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Hao, Yan
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Leandri, Valentina
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Svensson, Per H.
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden;RISE Surface Proc Formulat, Forskargatan 20j, SE-15136 Sodertalje, Sweden.
    Furao, Istvan
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Lund, Torben
    Roskilde Univ, Dept Sci & Environm, DK-4000 Roskilde, Denmark.
    Kloo, Lars
    KTH Royal Inst Technol, Dept Chem, Div Appl Phys Chem, SE-10044 Stockholm, Sweden.
    Light-induced electrolyte improvement in cobalt tris(bipyridine)-mediated dye-sensitized solar cells2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 33, p. 19495-19505Article in journal (Refereed)
    Abstract [en]

    Lithium-ion-free tris(2,2 '-bipyridine) Co(ii/iii)-mediated electrolytes have previously been proposed for long-term stable dye-sensitized solar cells (DSSCs). Such redox systems also offer an impressive DSSC performance improvement under light soaking exposure, manifested by an increase in photocurrent and fill factor without the expense of decreasing photovoltage. Kinetic studies show that charge transfer and ion diffusion at the electrode/electrolyte interface are improved due to the light exposure. Control experiments reveal that the light effect is unambiguously associated with electrolyte components, [Co(bpy)(3)](3+) and the Lewis-base additive tert-butylpyridine (TBP). Electrochemical and spectroscopic investigation of the [Co(bpy)(3)](3+)/TBP mixtures points out that the presence of TBP, which retards the electrolyte diffusion, however causes an irreversible redox reaction of [Co(bpy)(3)](3+) upon light exposure that improves the overall conductivity. This discovery not only provides a new strategy to mitigate the typical J(sc)-V-oc trade-off in Co(ii/iii)-mediated DSSCs but also highlights the importance of investigating the photochemistry of a photoelectrochemical system.

  • 29.
    Gupta, Divyani
    et al.
    Indian Inst Technol Ropar, Dept Chem, Rupnagar 140001, Punjab, India..
    Chakraborty, Sudip
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Harish Chandra Res Inst HRI, Allahabad Chhatnag Rd, Jhunsi 211019, Prayagraj, India..
    Amorim, Rodrigo G.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Univ Fed Fluminense UFF, Dept Fis, ICEx, Volta Redonda, RJ, Brazil..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Indian Inst Technol Ropar, Dept Phys, Rupnagar 140001, Punjab, India..
    Nagaiah, Tharamani C.
    Indian Inst Technol Ropar, Dept Chem, Rupnagar 140001, Punjab, India..
    Local electrocatalytic activity of PtRu supported on nitrogen-doped carbon nanotubes towards methanol oxidation by scanning electrochemical microscopy2021In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 9, no 37, p. 21291-21301Article in journal (Refereed)
    Abstract [en]

    Nitrogen-doped carbon nanotubes (NCNTs) were synthesized by treating HNO3-oxidized carbon nanotubes (CNTs) in an NH3 flow at different temperatures. PtRu nanoparticles were decorated over NCNTs. The PtRu catalysts were prepared by an impregnation-reduction method from metal chloride precursors with a total metal loading of about 10 wt%. The electrocatalytic activity with respect to methanol oxidation was studied using electrochemical and scanning electrochemical microscopy (SECM) measurements. Transmission electron microscopy revealed the spherical shape and narrow particle size distribution of the PtRu particles over NCNTs with average particle sizes of similar to 3-5 nm. A detailed X-ray photoelectron spectroscopy study was performed to quantitatively identify different nitrogen functional groups and to evaluate their role in the observed enhanced catalytic activity towards methanol oxidation. The determination of the local electrocatalytic activity of the proposed catalyst towards methanol oxidation and simultaneous evaluation of the intermediates produced during methanol oxidation were achieved using SECM. Density functional theory studies were performed to understand the adsorption sites of methanol and intermediates on different reactive sites and to investigate possible reaction mechanisms.

  • 30.
    Gupta, Divyani
    et al.
    Indian Inst Technol, Dept Chem, Rupnagar 140001, Punjab, India..
    Kafle, Alankar
    Indian Inst Technol, Dept Chem, Rupnagar 140001, Punjab, India..
    Kaur, Sukhjot
    Indian Inst Technol, Dept Chem, Rupnagar 140001, Punjab, India..
    Mohanty, Prajna Parimita
    Indian Inst Technol, Dept Phys, Rupnagar 140001, Punjab, India.;HBNI, Mat Theory Energy Scavenging MATES Lab, Harish Chandra Res Inst HRI Allahabad, Chhatnag Rd, Prayagraj 211019, Allahabad, India..
    Das, Tisita
    HBNI, Mat Theory Energy Scavenging MATES Lab, Harish Chandra Res Inst HRI Allahabad, Chhatnag Rd, Prayagraj 211019, Allahabad, India..
    Chakraborty, Sudip
    HBNI, Mat Theory Energy Scavenging MATES Lab, Harish Chandra Res Inst HRI Allahabad, Chhatnag Rd, Prayagraj 211019, Allahabad, India..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Indian Inst Technol, Dept Phys, Rupnagar 140001, Punjab, India.
    Nagaiah, Tharamani C.
    Indian Inst Technol, Dept Chem, Rupnagar 140001, Punjab, India..
    High yield selective electrochemical conversion of N-2 to NH(3)via morphology controlled silver phosphate under ambient conditions2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 38, p. 20616-20625Article in journal (Refereed)
    Abstract [en]

    Development of a highly active catalyst for the synthesis of ammonia via the electrochemical dinitrogen reduction reaction (e-NRR) is an immense challenge. We report the modification of metallic Ag with inorganic phosphate to obtain Ag3PO4 as an effective electrocatalyst for the e-NRR in alkaline media under ambient conditions. The designed Ag3PO4 catalyst can effectually suppress the HER. The e-NRR activity was improved by fine-tuning the morphology by a template free one-pot synthesis. The synthesised Ag3PO4 having cuboidal morphology is shown to have superior activity and stability towards the e-NRR witnessed from a high faradaic efficiency of 26.67%, yield rate of 456.75 mu g h(-1) mg(cat)(-1) and TOF value of 0.46 h(-1) at a positive potential of 0 V vs. RHE in 0.1 M KOH. Careful examination of any N-contaminants present in catalyst/electrolyte/gas-feed is carried out by UV-vis spectroscopy and gas-purification methods prior to e-NRR measurements to eliminate any false NH3 production. Also, the true source of NH3 production is confirmed by means of N-15-isotope labelling experiments via(1)H-NMR spectroscopy.

  • 31.
    Gupta, Divyani
    et al.
    Indian Inst Technol Ropar, Dept Chem, Rupnagar 140001, Punjab, India..
    Kafle, Alankar
    Indian Inst Technol Ropar, Dept Chem, Rupnagar 140001, Punjab, India..
    Mohanty, Prajna Parimita
    Indian Inst Technol Ropar, Dept Phys, Rupnagar 140001, Punjab, India.;Harish Chandra Res Inst HRI Allahabad, HBNI, Mat Theory Energy Scavenging MATES Lab, Chhatnag Rd, Prayagraj 211019, India..
    Das, Tisita
    Harish Chandra Res Inst HRI Allahabad, HBNI, Mat Theory Energy Scavenging MATES Lab, Chhatnag Rd, Prayagraj 211019, India..
    Chakraborty, Sudip
    Harish Chandra Res Inst HRI Allahabad, HBNI, Mat Theory Energy Scavenging MATES Lab, Chhatnag Rd, Prayagraj 211019, India..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Indian Inst Technol Ropar, Dept Phys, Rupnagar 140001, Punjab, India..
    Nagaiah, Tharamani C.
    Indian Inst Technol Ropar, Dept Chem, Rupnagar 140001, Punjab, India..
    Self-powered NH3 synthesis by trifunctional Co2B-based high power density Zn-air batteries2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 23, p. 12223-12235Article in journal (Refereed)
    Abstract [en]

    The electrochemical production of NH3 by Zn-air batteries is a viable and economical approach to realize sustainable and competent energy conversion. We report the environment friendly, cost-effective, and energy efficient sonochemical synthesis of amorphous Co2B nanosheets for trifunctional electrocatalysis. The catalyst exhibits a high NH3 yield rate (2.98 mg h(-1) mg(cat.)(-1)), F.E (20.45%), and TOF of 0.74 h(-1) at -0.3 V vs. RHE, thereby unveiling an outstanding performance for the artificial ammonia synthesis. The reliable and true NH3 production is premediated by following rigorous protocol that involves the purification of gas supplies, elimination of N-contaminants, and quantification of NH3 by different methods, UV-Vis spectroscopy and N-15(2) isotope labelling experiments. More interestingly, DFT calculations on the Co2B catalyst surface shed light on the efficient NRR owing to the presence of Co active sites and possible HER suppression. The optimized Co2B catalyst shows outstanding oxygen bifunctional activity. When employed as an air-cathode for Zn-air batteries, it exhibited remarkable electrocatalytic activity delivering an open circuit potential of 1.45 V with a high power density of 500 mW cm(-2) and an energy density of 1078 W h kg(-1), which can perform NH3 generation with an overall NH3 production yield rate of 1.048 mg h(-1) mg(cat.)(-1).

  • 32.
    Günther, Tyran
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Oka, Kouki
    Olsson, Sandra K.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
    Åhlén, Michelle
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Materials Science and Engineering, Nanotechnology and Functional Materials.
    Tohnai, Norimitsu
    Emanuelsson, Rikard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
    Redox-site accessibility of composites containing a 2D redox-active covalent organic framework: from optimization to application2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 26, p. 13923-13931Article in journal (Refereed)
    Abstract [en]

    Redox-active covalent organic frameworks (RACOFs) can be employed in various functional materials and enesrgy applications. A crucial performance or efficiency indicator is the percentage of redox centres that can be utilised. Herein, the term redox-site accessibility (RSA) is defined and shown to be an effective metric for developing and optimising a 2D RACOF (viz., TpOMe-DAQ made from 2,4,6-trimethoxy-1,3,5-benzenetricarbaldehyde [TpOMe] and 2,6-diaminoanthraquinone [DAQ]) as an anode material for potential organic-battery applications. Pristine TpOMe-DAQ utilises only 0.76% of its redox sites, necessitating the use of conductivity-enhancement strategies such as blending it with different conductive carbons, or performing in situ polymerisation with EDOT (3,4-ethylenedioxythiophene) to form a conductive polymer. While conductive carbon-RACOF composites showed a modest RSA improvement of 4.0%, conductive polymer-RACOF composites boosted the redox-site usage (RSA) to 90% at low mass loadings. The material and electrochemical characteristics of the conductive polymer-RACOF composite containing more-than-necessary conductive polymer showed a reduced surface area but almost identical electrochemical behaviour, compared to the optimal ratio. The high RSA of the optimally loaded composite was replicated in a RACOF-air battery with over 90% active redox sites. We believe that the reported approach and methods, which can be employed on a milligram scale, could serve as a general guide for the electrification and characterisation of RACOFs, as well as for other redox-active porous polymers.

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  • 33.
    Hagfeldt, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Cornelissen, Jeroen
    Univ Twente, Enschede, Netherlands..
    Stingelin, Natalie
    Georgia Inst Technol Univ, Atlanta, GA USA..
    Looking back at the 10th anniversary year of Journal of Materials Chemistry A, B and C2024In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 12, no 1, p. 16-18Article in journal (Other academic)
    Abstract [en]

    The Editors-in-Chief for Journal of Materials Chemistry A, B and C look back at the 10th anniversary year and the celebratory activities that took place.

  • 34.
    Haque, Anamul
    et al.
    Ctr Nano & So Matter Sci CeNS, Bengaluru 562162, India.;Manipal Acad Higher Educ MAHE, Manipal 576104, India..
    Ershadrad, Soheil
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Chonamada, Trupthi Devaiah
    Ctr Nano & So Matter Sci CeNS, Bengaluru 562162, India.;Manipal Acad Higher Educ MAHE, Manipal 576104, India.;Univ & Leeds CMAC, Sch Chem & Proc Engn, Leeds LS29JT, W Yorkshire, England..
    Saha, Dipankar
    Univ & Leeds CMAC, Sch Chem & Proc Engn, Leeds LS29JT, W Yorkshire, England.;Rutherford Appleton Lab, Res Complex Harwell RCaH, Harwell OX11 0FA, Oxon, England..
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Santra, Pralay K.
    Ctr Nano & So Matter Sci CeNS, Bengaluru 562162, India..
    Vacancy assisted growth of copper tantalum sulfide nanocrystals2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 37, p. 19925-19934Article in journal (Refereed)
    Abstract [en]

    Cu-based ternary chalcogenides have received significant interest as an alternative to conventional photovoltaic materials. CuInS2 and CuInSe2 are the most studied copper-based ternary chalcogenides for photovoltaics. Recently, copper tantalum sulfide (CuTaS3) has been proposed as a potential light absorber for photovoltaics. The synthesis conditions and growth mechanism of ternary systems control the final composition and crystal structure. However, such studies have not been explored for copper tantalum sulfides. Here, we studied the formation and growth mechanism of Cu3TaS4 nanocrystals (NCs) primarily using X-ray diffraction, transmission electron microscopy, and density functional theory (DFT) calculations. The reactions proceed via the formation of cubic Cu2-xS NCs due to soft Lewis acid - soft Lewis base interaction. The Cu2-xS have Cu vacancies, which can be controlled by the relative concentration of the Cu precursor. Ta incorporation occurs in the Cu2-xS NCs at Cu vacancy sites, followed by the diffusion of Ta by replacing Cu into the lattice. Low packing of atoms in Cu3TaS4 provides suitable diffusion channels for Ta and Cu atoms. The diffusion barriers of Ta atoms outweigh that of Cu atoms, implying a reaction rate controlled by Ta diffusion. Thus by varying the relative Cu precursor concentration, the concentration of Cu-vacancies in Cu2-xS can be tuned, which controls the growth rate of Cu3TaS4. Understanding of the growth mechanism obtained in this paper will significantly contribute to the rational synthesis of various Cu-based ternary chalcogenides that is not possible by direct synthesis and hence will have an impact on potential applications in photovoltaics and photocatalysis.

  • 35.
    Hernández, Guiomar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lee, Tian Khoon
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry. Univ Kebangsaan Malaysia, Fac Sci & Technol, Dept Chem Sci, Ukm Bangi 43000, Selangor, Malaysia.
    Erdélyi, Máté
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mindemark, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Do non-coordinating polymers function as host materials for solid polymer electrolytes?: The case of PVdF-HFP2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 28, p. 15329-15335Article in journal (Refereed)
    Abstract [en]

    In the search for novel solid polymer electrolytes (SPEs), primarily targeting battery applications, a range of different polymers is currently being explored. In this context, the non-coordinating poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) polymer is a frequently utilized system. Considering that PVdF-HFP should be a poor solvent for cation salts, it is counterintuitive that this is a functional host material for SPEs. Here, we do an in-depth study of the salt dissolution properties and ionic conductivity of PVdF-HFP-based electrolytes, using two different fabrication methods and also employing a low-molecular-weight solvent analogue. It is seen that PVdF-HFP is remarkably poor as an SPE host, despite its comparatively high dielectric constant, and that the salt dissolution properties instead are controlled by fluorophilic interactions of the anion with the polymer.

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  • 36.
    Iakunkov, Artem
    et al.
    Umea Univ, Dept Phys, S-90187 Umea, Sweden.
    Sun, Jinhua
    Umea Univ, Dept Phys, S-90187 Umea, Sweden.
    Rebrikova, Anastasia
    Moscow MV Lomonosov State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Korobov, Mikhail
    Moscow MV Lomonosov State Univ, Dept Chem, Leninskie Gory 1-3, Moscow 119991, Russia.
    Klechikov, Alexey
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. Umea Univ, Dept Phys, S-90187 Umea, Sweden.
    Vorobiev, Alexei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Boulanger, Nicolas
    Umea Univ, Dept Phys, S-90187 Umea, Sweden.
    Talyzin, Alexandr V.
    Umea Univ, Dept Phys, S-90187 Umea, Sweden.
    Swelling of graphene oxide membranes in alcohols: effects of molecule size and air ageing2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 18, p. 11331-11337Article in journal (Refereed)
    Abstract [en]

    Swelling of Hummers graphene oxide (HGO) membranes in a set of progressively longer liquid alcohols (methanol to 1-nonanol) was studied using synchrotron radiation XRD after air ageing over prolonged periods of time. Both precursor graphite oxides and freshly prepared HGO membranes were found to swell in the whole set of nine liquid alcohols with an increase of interlayer spacing from approximate to 7 angstrom (solvent free) up to approximate to 26 angstrom (in 1-nonanol). A pronounced effect of ageing on swelling in alcohols was found for HGO membranes stored in air. The HGO membranes aged for 0.5-1.5 years show progressively slower swelling kinetics, a non-monotonic decrease of saturated swelling in some alcohols and complete disappearance of swelling for alcohol molecules larger than hexanol. Moreover, the HGO membranes stored under ambient conditions for 5 years showed a nearly complete absence of swelling in all alcohols but preserved swelling in water. In contrast, precursor graphite oxide powder showed unmodified swelling in alcohols even after 4 years of ageing. Since the swelling defines the size of permeation channels, the ageing effect is one of the important parameters which could explain the strong variation in reported filtration/separation properties of GO membranes. The time and conditions of air storage require standardization for better reproducibility of results related to performance of GO membranes in various applications. The ageing of GO membranes can be considered not only as a hindrance/degradation for certain applications, but also as a method to tune the swelling properties of HGO membranes for better selectivity in sorption of solvents and for achieving better selective permeability.

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  • 37.
    Jain, Sagar Motilal
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Johansson, Erik M. J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Park, Byung-Wook
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Rensmo, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and condensed matter physics.
    Edvinsson, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Vapor phase conversion of PbI2 to CH3NH3PbI3: spectroscopic evidence for formation of an intermediate phase2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 7, p. 2630-2642Article in journal (Refereed)
    Abstract [en]

    The formation of CH3NH3PbI3 (MAPbI(3)) from its precursors is probably the most significant step in the control of the quality of this semiconductor perovskite material, which is highly promising for photovoltaic applications. Here we investigated the transformation of spin coated PbI2 films to MAPbI(3) using a reaction with MAI in vapor phase, referred to as vapor assisted solution process (VASP). The presence of a mesoporous TiO2 scaffold on the substrate was found to speed up reaction and led to complete conversion of PbI2, while reaction on glass substrates was slower, with some PbI2 remaining even after prolonged reaction time. Based on data from UV-visible spectroscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, the formation of an X-ray amorphous intermediate phase is proposed, which is identified by an increasing absorption from 650 to 500 nm in the absorption spectrum. This feature disappears upon long reaction times for films on planar substrates, but persists for films on mesoporous TiO2. Poor solar cell performance of planar VASP prepared devices was ascribed to PbI2 remaining in the film, forming a barrier between the perovskite layer and the compact TiO2/FTO contact. Good performance, with efficiencies up to 13.3%, was obtained for VASP prepared devices on mesoporous TiO2.

  • 38.
    Jiang, Roger
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    The Impact of Non-Uniform Photogeneration on Mass Transport in Dye-Sensitised Solar Cells2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 22, p. 10264-10276Article in journal (Refereed)
    Abstract [en]

    Following the introduction of cobalt(II/III)tris(2,2'-bipyridyl)-based redox mediators, dye-sensitised solar cells (DSSCs) have greatly advanced in power conversion efficiency (PCE). However, significant limiting factors include the fast electron recombination and slow mass transport of the oxidised redox mediator ([Co(bipy)(3)](3+)). In this work, the effect of non-uniform photogeneration on the mass transport of [Co(bipy)(3)](3+) through an electrolyte-infiltrated mesoporous TiO2 film was investigated. Different illumination conditions were used to control the photogeneration profile and the subsequent spatial distribution of [Co(bipy)(3)](3+) throughout the TiO2 film. They included parameters such as the light intensity, substrate-electrode/electrolyte-electrode (SE/EE) illumination direction, wavelength, and TiO2 photoanode thickness. Using large and small optical perturbation photocurrent transients, electron recombination kinetics with [Co(bipy)(3)](3+) were analysed in the time domain. Importantly, strong SE-absorption was shown to significantly contribute to the gradual depletion of [Co(bipy)(3)](3+) at the counter electrode, along with an increased film thickness and light intensity, resulting in excess recombination with [Co(bipy)(3)](3+) on the 10(-2)-1 s timescale. Furthermore, charge extraction current decay transients showed that a substantial amount of [Co(bipy)(3)](3+) can accumulate inside the TiO2 film, resulting in significant recombination at the collecting fluorine-doped tin oxide (FTO) contact on the 10(-3)-10(-2) s timescale. The sub-linear scaling of recombination with light intensity leads to deviating trends in charge extraction and electron transport measurements. Mass transport limitations and recombination losses at the FTO can be significantly reduced by maximising light absorption from the EE-side, which can increase PCE and reduce J-V hysteresis.

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  • 39.
    Jorner, Kjell
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Dreos, Ambra
    Chalmers, Dept Chem & Chem Engn, Kemigarden 4, SE-41296 Gothenburg, Sweden..
    Emanuelsson, Rikard
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    El Bakouri, Ouissam
    Univ Girona, Dept Quim, IQCC, Campus Montilivi, Girona 17003, Spain..
    Fernández Galván, Ignacio
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Uppsala Univ, UC3, Box 523, SE-75120 Uppsala, Sweden..
    Borjesson, Karl
    Chalmers, Dept Chem & Chem Engn, Kemigarden 4, SE-41296 Gothenburg, Sweden.;Univ Gothenburg, Dept Chem & Mol Biol, Kemigarden 4, SE-41296 Gothenburg, Sweden..
    Feixas, Ferran
    Univ Girona, Dept Quim, IQCC, Campus Montilivi, Girona 17003, Spain..
    Lindh, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry. Uppsala Univ, UC3, Box 523, SE-75120 Uppsala, Sweden..
    Zietz, Burkhard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Moth-Poulsen, Kasper
    Chalmers, Dept Chem & Chem Engn, Kemigarden 4, SE-41296 Gothenburg, Sweden..
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Unraveling factors leading to efficient norbornadiene-quadricyclane molecular solar-thermal energy storage systems2017In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, no 24, p. 12369-12378Article in journal (Refereed)
    Abstract [en]

    Developing norbornadiene-quadricyclane (NBD-QC) systems for molecular solar-thermal (MOST) energy storage is often a process of trial and error. By studying a series of norbornadienes (NBD-R-2) doubly substituted at the C7-position with R = H, Me, and iPr, we untangle the interrelated factors affecting MOST performance through a combination of experiment and theory. Increasing the steric bulk along the NBD-R-2 series gave higher quantum yields, slightly red-shifted absorptions, and longer thermal lifetimes of the energy-rich QC isomer. However, these advantages are counterbalanced by lower energy storage capacities, and overall R = Me appears most promising for short-term MOST applications. Computationally we find that it is the destabilization of the NBD isomer over the QC isomer with increasing steric bulk that is responsible for most of the observed trends and we can also predict the relative quantum yields by characterizing the S-1/S-0 conical intersections. The significantly increased thermal half-life of NBD-iPr(2) is caused by a higher activation entropy, highlighting a novel strategy to improve thermal half-lives of MOST compounds and other photo-switchable molecules without affecting their electronic properties. The potential of the NBD-R-2 compounds in devices is also explored, demonstrating a solar energy storage efficiency of up to 0.2%. Finally, we show how the insights gained in this study can be used to identify strategies to improve already existing NBD-QC systems.

  • 40.
    Kan, Zhipeng
    et al.
    Ist Italiano Tecnol, Ctr Nano Sci & Technol PoliMi, Via Giovanni Pascoli 70-3, I-20133 Milan, Italy..
    Colella, Letizia
    Politecn Milan, Dipartimento Chim Mat & Ing Chim G Natta, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy.;Osserv Astron Brera, INAF, Via Bianchi 46, I-23807 Merate, Italy..
    Canesi, Eleonora V.
    Ist Italiano Tecnol, Ctr Nano Sci & Technol PoliMi, Via Giovanni Pascoli 70-3, I-20133 Milan, Italy.;Politecn Milan, Dipartimento Chim Mat & Ing Chim G Natta, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy..
    Vorobiev, Alexei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics.
    Skrypnychuk, Vasyl
    Umea Univ, Nanoengineered Mat & Organ Elect Lab, Umea, Sweden..
    Terraneo, Giancarlo
    Ist Italiano Tecnol, Ctr Nano Sci & Technol PoliMi, Via Giovanni Pascoli 70-3, I-20133 Milan, Italy.;Politecn Milan, Dipartimento Chim Mat & Ing Chim G Natta, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy..
    Barbero, David R.
    Umea Univ, Nanoengineered Mat & Organ Elect Lab, Umea, Sweden..
    Bertarelli, Chiara
    Ist Italiano Tecnol, Ctr Nano Sci & Technol PoliMi, Via Giovanni Pascoli 70-3, I-20133 Milan, Italy.;Politecn Milan, Dipartimento Chim Mat & Ing Chim G Natta, Piazza Leonardo da Vinci 32, I-20133 Milan, Italy..
    MacKenzie, Roderick C. I.
    Univ Nottingham, Fac Engn, Univ Pk, Nottingham NG7 2RD, England..
    Keivanidis, Panagiotis E.
    Cyprus Univ Technol, Dept Mech Engn & Mat Sci & Engn, 45 Kitiou Kyprianou Str, CY-3041 Limassol, Cyprus..
    Charge transport control via polymer polymorph modulation in ternary organic photovoltaic composites2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 4, p. 1195-1201Article in journal (Refereed)
    Abstract [en]

    The control on the charge transport properties of ternary organic photovoltaic P3HT : PCBM : QBT devices is enabled by modulating the distribution of P3HT polymorphs in the device photoactive layers. Negligible amounts of QBT induce striking modifications in the P3HT lamellar stacking direction, forming both densely packed and non-densely packed P3HT chains. The former reduce the charge carrier recombination rate, enabling an increased fill factor and short-circuit device photocurrent.

  • 41.
    Kim, Min-Jeong
    et al.
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Lee, Won-Yong
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Solid-State Electronics. Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Kang, Min-Sung
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Kim, Si-Hoo
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Cho, Jung-Min
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Kim, Yun-Ho
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Choi, Jae-Won
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Park, No-Won
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Kim, Gil-Sung
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Yoon, Young-Gui
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Lee, Sang-Kwon
    Chung Ang Univ, Dept Phys, Seoul 06974, South Korea.;Chung Ang Univ, Ctr Berry Curvature based New Phenomena, Seoul 06974, South Korea..
    Intrinsic Seebeck coefficients of 2D polycrystalline PtSe2 semiconducting films through two-step annealing2023In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 11, p. 5714-5724Article in journal (Refereed)
    Abstract [en]

    Because of the high contact resistance between a metal and a film, evaluating the intrinsic Seebeck coefficient of large-area two-dimensional (2D) semiconducting films with high-resistance is challenging. Here, we report a simple scheme to measure the large-area Seebeck coefficients of 2D polycrystalline platinum diselenide (PtSe2) thin films, whose electrical resistance (>2 M omega) is too high to measure the thermoelectric (TE) properties, by thermal annealing. As-prepared PtSe2 thin films deposited on sapphire substrates and treated by a two-step thermal annealing process at 574 K exhibited an intrinsic Seebeck coefficient > similar to 160 mu V K-1, which is 400% higher than that of the single-crystalline PtSe2 bulk, under a temperature gradient of up to 5 K along the samples. In addition, we confirm that the in-plane Seebeck coefficient of the two-step annealed samples was independent of the metal electrode. In addition, the role of thermal annealing in intrinsically-high-resistance 2D PtSe2 semiconducting films based on the atomic-scale crystallographic characteristics of these films and the measured contact resistance between the metal and PtSe2 layer is further discussed. Our finding represents an important achievement in understanding and measuring the Seebeck effect of high-TE-performance 2D layered transition metal dichalcogenide materials.

  • 42.
    Kokkonen, Mikko
    et al.
    Univ Oulu, Microelect Res Unit, Fac Informat Technol & Elect Engn, POB 4500, FI-90014 Oulu, Finland..
    Talebi, Parisa
    Univ Oulu, Nano & Mol Syst Res Unit, FIN-90014 Oulu, Finland..
    Zhou, Jin
    Univ Oulu, Microelect Res Unit, Fac Informat Technol & Elect Engn, POB 4500, FI-90014 Oulu, Finland..
    Asgari, Somayyeh
    Univ Oulu, Optoelect & Measurement Tech Res Unit, Fac Informat Technol & Elect Engn, Oulu, Finland..
    Soomro, Sohail Ahmed
    Univ Oulu, Dept Informat Technol & Elect Engn, Ctr Ubiquitous Comp, Oulu, Finland..
    Elsehrawy, Farid
    Aalto Univ, Dept Appl Phys, New Energy Technol Res Grp, POB 15100, FI-00076 Aalto, Finland..
    Halme, Janne
    Aalto Univ, Dept Appl Phys, New Energy Technol Res Grp, POB 15100, FI-00076 Aalto, Finland..
    Ahmad, Shahzada
    BCMat Basque Ctr Mat Applicat & Nanostruct, UPV EHU Sci Pk, Leioa 48940, Spain.;Basque Fdn Sci, IKERBASQUE, Bilbao 48009, Spain..
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hashmi, Syed Ghufran
    Univ Oulu, Microelect Res Unit, Fac Informat Technol & Elect Engn, POB 4500, FI-90014 Oulu, Finland..
    Advanced research trends in dye-sensitized solar cells2021In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 9, no 17, p. 10527-10545Article, review/survey (Refereed)
    Abstract [en]

    Dye-sensitized solar cells (DSSCs) are an efficient photovoltaic technology for powering electronic applications such as wireless sensors with indoor light. Their low cost and abundant materials, as well as their capability to be manufactured as thin and light-weight flexible solar modules highlight their potential for economic indoor photovoltaics. However, their fabrication methods must be scaled to industrial manufacturing with high photovoltaic efficiency and performance stability under typical indoor conditions. This paper reviews the recent progress in DSSC research towards this goal through the development of new device structures, alternative redox shuttles, solid-state hole conductors, TiO2 photoelectrodes, catalyst materials, and sealing techniques. We discuss how each functional component of a DSSC has been improved with these new materials and fabrication techniques. In addition, we propose a scalable cell fabrication process that integrates these developments to a new monolithic cell design based on several features including inkjet and screen printing of the dye, a solid state hole conductor, PEDOT contact, compact TiO2, mesoporous TiO2, carbon nanotubes counter electrode, epoxy encapsulation layers and silver conductors. Finally, we discuss the need to design new stability testing protocols to assess the probable deployment of DSSCs in portable electronics and internet-of-things devices.

  • 43.
    Krishna, Anurag
    et al.
    Nanyang Technol Univ, Interdisciplinary Grad Sch, Energy Res Inst, Singapore 639798, Singapore..
    Sabba, Dharani
    Energy Res Inst NTU ERI N, Res Techno Plaza,X Frontier Block,Level 5, Singapore 637553, Singapore..
    Yin, Jun
    Nanyang Technol Univ, Div Phys & Appl Phys, 21 Nanyang Link, Singapore 637371, Singapore..
    Bruno, Annalisa
    Energy Res Inst NTU ERI N, Res Techno Plaza,X Frontier Block,Level 5, Singapore 637553, Singapore..
    Antila, Liisa J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Soci, Cesare
    Nanyang Technol Univ, Div Phys & Appl Phys, 21 Nanyang Link, Singapore 637371, Singapore..
    Mhaisalkar, Subodh
    Energy Res Inst NTU ERI N, Res Techno Plaza,X Frontier Block,Level 5, Singapore 637553, Singapore.;Nanyang Technol Univ, Sch Mat Sci & Engn, Nanyang Ave, Singapore 639798, Singapore..
    Grimsdale, Andrew C.
    Energy Res Inst NTU ERI N, Res Techno Plaza,X Frontier Block,Level 5, Singapore 637553, Singapore.;Nanyang Technol Univ, Sch Mat Sci & Engn, Nanyang Ave, Singapore 639798, Singapore..
    Facile synthesis of a hole transporting material with a silafluorene core for efficient mesoscopic CH3NH3PbI3 perovskite solar cells2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 22, p. 8750-8754Article in journal (Refereed)
    Abstract [en]

    A novel electron-rich small-molecule, 4,4'-(5,5-dihexyl-5H-dibenzo[b,d]silole-3,7-diyl)bis(N,N-bis(4-methoxyphenyl)aniline) (S101), containing silafluorene as the core with arylamine side groups, has been synthesized via a short efficient route. When S101 was incorporated into a CH3NH3PbI3 perovskite solar cell as a hole transporting material (HTM), a short circuit photocurrent density (J(sc)) of 18.9 mA cm(-2), an open circuit voltage (V-oc) of 0.92 V, and a fill factor (FF) of 0.65 contributing to an overall power conversion efficiency (PCE) of similar to 11% which is comparable to the PCE obtained using the current state-of-the-art HTM 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) (eta = 12.3%) were obtained. S101 is thus a promising HTM with the potential to replace the expensive spiro-OMeTAD due to its comparable performance and much simpler and less expensive synthesis route.

  • 44.
    Källquist, Ida
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Le Ruyet, Ronan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Liu, Haidong
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Mogensen, Ronnie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lee, Ming-Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Naylor, Andrew J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Advances in studying interfacial reactions in rechargeable batteries by photoelectron spectroscopy2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 37, p. 19466-19505Article, review/survey (Refereed)
    Abstract [en]

    Many of the challenges faced in the development of lithium-ion batteries (LIBs) and next-generation technologies stem from the (electro)chemical interactions between the electrolyte and electrodes during operation. It is at the electrode-electrolyte interfaces where ageing mechanisms can originate through, for example, the build-up of electrolyte decomposition products or the dissolution of metal ions. In pursuit of understanding these processes, X-ray photoelectron spectroscopy (XPS) has become one of the most important and powerful techniques in a large collection of available tools. As a highly surface-sensitive technique, it is often thought to be the most relevant in characterising the interfacial reactions that occur inside modern rechargeable batteries. This review tells the story of how XPS is employed in day-to-day battery research, as well as highlighting some of the most recent innovative in situ and operando methodologies developed to probe battery materials in ever greater detail. A large focus is placed not only on LIBs, but also on next-generation materials and future technologies, including sodium- and potassium-ion, multivalent, and solid-state batteries. The capabilities, limitations and practical considerations of XPS, particularly in relation to the investigation of battery materials, are discussed, and expectations for its use and development in the future are assessed.

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  • 45.
    Lacnjevac, Uros
    et al.
    Univ Belgrade, Inst Multidisciplinary Res, Kneza Viseslava 1, Belgrade 11030, Serbia..
    Vasilic, Rastko
    Univ Belgrade, Fac Phys, Studentski Trg 12-16, Belgrade 11000, Serbia..
    Dobrota, Ana
    Univ Belgrade, Fac Phys Chem, Studentski Trg 12-16, Belgrade 11000, Serbia..
    Durdic, Sladana
    Univ Belgrade, Fac Chem, Studentski Trg 12-16, Belgrade 11000, Serbia..
    Tomanec, Ondrej
    Reg Ctr Adv Technol & Mat, Slechtitelu 27, Olomouc 78371, Czech Republic..
    Zboril, Radek
    Reg Ctr Adv Technol & Mat, Slechtitelu 27, Olomouc 78371, Czech Republic..
    Mohajernia, Shiva
    Univ Erlangen Nurnberg, Dept Mat Sci, WW4 LKO, Martensstr 7, D-91058 Erlangen, Germany..
    Nguyen, Nhat Truong
    Skorodumova, Natalia V.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KTH Royal Inst Technol, Sch Ind Engn & Management, Dept Mat Sci & Engn, Brinellvagen 23, S-10044 Stockholm, Sweden..
    Manojlovic, Dragan
    Univ Belgrade, Fac Chem, Studentski Trg 12-16, Belgrade 11000, Serbia..
    Elezovic, Nevenka
    Univ Belgrade, Inst Multidisciplinary Res, Kneza Viseslava 1, Belgrade 11030, Serbia..
    Pasti, Igor
    Univ Belgrade, Fac Phys Chem, Studentski Trg 12-16, Belgrade 11000, Serbia.;KTH Royal Inst Technol, Sch Ind Engn & Management, Dept Mat Sci & Engn, Brinellvagen 23, S-10044 Stockholm, Sweden..
    Schmuki, Patrik
    Reg Ctr Adv Technol & Mat, Slechtitelu 27, Olomouc 78371, Czech Republic.;Univ Erlangen Nurnberg, Dept Mat Sci, WW4 LKO, Martensstr 7, D-91058 Erlangen, Germany..
    High-performance hydrogen evolution electrocatalysis using proton-intercalated TiO2 nanotube arrays as interactive supports for Ir nanoparticles2020In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 8, no 43, p. 22773-22790Article in journal (Refereed)
    Abstract [en]

    Developing ultraefficient electrocatalytic materials for the hydrogen evolution reaction (HER) with low content of expensive platinum group metals (PGMs) via low-energy-input procedures is the key to the successful commercialization of green water electrolysis technologies for sustainable production of high-purity hydrogen. In this study, we report a facile room-temperature synthesis of ultrafine metallic Ir nanoparticles on conductive, proton-intercalated TiO2 nanotube (H-TNT) arrays via galvanic displacement. A series of experiments demonstrate that a controlled transformation of the H-TNT surface microstructure from neat open-top tubes to disordered nanostripe bundles ("nanograss") is highly beneficial for providing an abundance of exposed Ir active sites. Consequently, for nanograss-engineered composites, outstanding HER activity metrics are achieved even at very low Ir(iii) precursor concentrations. An optimum Ir@TNT cathode loaded with 5.7 mu g(Ir) cm(-2) exhibits an overpotential of -63 mV at -100 mA cm(-2) and a mass activity of 34 A mg(Ir)(-1) at -80 mV under acidic conditions, along with excellent catalytic durability and structural integrity. Density functional theory (DFT) simulations reveal that the hydrogen-rich TiO2 surface not only stabilizes the deposited Ir and weakens its H binding strength to a moderate intensity, but also actively takes part in the HER mechanism by refreshing the Ir catalytic sites near the Ir|H-TiO2 interface, thus substantially promoting H-2 generation. The comprehensive characterization combined with theory provides an in-depth understanding of the electrocatalytic behavior of H-TNT supported PGM nanoparticles and demonstrates their high potential as competitive electrocatalyst systems for the HER.

  • 46.
    Lal, Sohan
    et al.
    Indian Inst Technol, Dept Chem, Bombay 400076, Maharashtra, India..
    Mallick, Lovely
    Indian Inst Technol, Dept Mech Engn, Bombay 400076, Maharashtra, India..
    Rajkumar, Sundaram
    Indian Inst Technol, Dept Chem, Bombay 400076, Maharashtra, India..
    Oommen, Oommen P.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Indian Inst Technol, Dept Chem, Bombay 400076, Maharashtra, India..
    Reshmi, Sasidharakurup
    Vikram Sarabhai Space Ctr, PCM Ent, Polymers & Special Chem Grp, Thiruvananthapuram 695022, Kerala, India..
    Kumbhakarna, Neeraj
    Indian Inst Technol, Dept Mech Engn, Bombay 400076, Maharashtra, India..
    Chowdhury, Arindrajit
    Indian Inst Technol, Dept Mech Engn, Bombay 400076, Maharashtra, India..
    Namboothiri, Irishi N. N.
    Indian Inst Technol, Dept Chem, Bombay 400076, Maharashtra, India..
    Synthesis and energetic properties of high-nitrogen substituted bishomocubanes2015In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 44, p. 22118-22128Article in journal (Refereed)
    Abstract [en]

    Synthesis, thermodynamic characterization, and energetic properties of three novel high-nitrogen bishomocubane-based compounds DADMBHC, DTetzBHC and DPTrizDMBHC are reported here. These compounds have higher heats of formation (HoFs) and higher energy densities as compared to traditional hydrocarbon fuels. Densities, gas phase HoF and their optimized molecular structure geometries were calculated with various levels of theory. In general, the calculated HoFs of these compounds turn out to be extremely high. Ballistic properties such as vacuum specific impulse and density vacuum specific impulse were calculated using the NASA Chemical Equilibrium and Applications utility. Propulsive properties were compared with liquid bipropellants (RP1) and solid propellants (AP) and explosive properties were compared with RDX. The density specific impulse demonstrated an improvement of 35 s for DADMBHC and DTetzBHC over standard liquid hydrocarbon HTPB, thus showing promise as possible monomers to replace HTPB as a fuel-binder. The density specific impulses of these compounds were also found to be significantly higher than that of RP1, e.g. that of DADMBHC was found to be higher by 84 s, making them potentially good candidates as propellants for use under volume-limited conditions. The detonation properties showed that these compounds have low potential as explosives. TGA, coupled with IR spectroscopy, revealed that DADMBHC and DPTrizDMBHC evaporate readily while DTetzBHC decomposes partially.

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  • 47.
    Li, Liansheng
    et al.
    Guangdong Provincial Key Laboratory of Fuel Cell Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China.
    Duan, Huanhuan
    Guangdong Provincial Key Laboratory of Fuel Cell Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China.
    Zhang, Leiting
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Deng, Yuanfu
    Guangdong Provincial Key Laboratory of Fuel Cell Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China;Guangdong Provincial Research Center of Electrochemical Energy Engineering, South China University of Technology, Guangzhou, 510640, PR China.
    Chen, Guohua
    Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China.
    Optimized functional additive enabled stable cathode and anode interfaces for high-voltage all-solid-state lithium batteries with significantly improved cycling performance2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 38, p. 20331-20342Article in journal (Refereed)
    Abstract [en]

    Functional additives play important roles in stabilizing the interfaces within all-solid-state lithium batteries (ASSLBs), equally vital as in liquid lithium ion batteries (LLIBs). However, they have not received as much attention as in LLIBs; especially the effects of a unique additive on both of cathode and anode interfaces are not clearly understood. Inspired by this idea, the effects of lithium difluoro(oxalate)borate (LiDFOB) and lithium bisoxalatodifluorophosphate (LiBODFP) on the stabilities of the cathode and anode interfaces within the assembled ASSLBs are systematically compared through a series of characterization techniques in this work. Owing to the different degrees of redox kinetics of the LiDFOB and LiBODFP additives, the as-formed cathode solid electrolyte interface (CEI) and anode solid electrolyte interface (SEI) films exhibit drastically different characteristics. Specifically, the LiDFOB-induced CEI film is unevenly distributed and unstable, while a uniform, thin and dense SEI film, delivering an outside-to-inside structure of organic lithium species-layer/LiF-rich layer/Li2O-rich layer, can be generated in the presence of LiDFOB. By contrast, the formed CEI film induced by the LiBODFP additive exhibits stable, uniformly distributed and thin characteristics. However, the LiBODFP-induced SEI film is flawed due to its slow reduction rate. To take full advantage of the electrochemical activities of LiBODFP and LiDFOB additives, a double-layer PEO-based composite solid electrolyte (CSE) with both additives is designed and fabricated. As a result, the assembled ASSLB with a single crystal LiNi0.6Co0.2Mn0.2 cathode and double-layer CSE shows a high specific capacity and ultra-high capacity retention (87.5% after 1340 cycles at 1C). This novel strategy of stabilizing different electrode/electrolyte interfaces using various functional additives is a promising method to enable ASSLBs with excellent performances.

  • 48.
    Li, Yuhan
    et al.
    Northeast Normal Univ, Inst Funct Mat, Fac Chem, Changchun 130024, Jilin, Peoples R China.;Beihua Univ, Coll Chem & Biol, Jilin 132013, Jilin, Peoples R China..
    Sun, Weiwei
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Liang, Jing
    Northeast Normal Univ, Inst Funct Mat, Fac Chem, Changchun 130024, Jilin, Peoples R China.;Northeast Normal Univ, Natl & Local United Engn Lab Power Battery, Changchun 130024, Jilin, Peoples R China..
    Sun, Hao
    Northeast Normal Univ, Inst Funct Mat, Fac Chem, Changchun 130024, Jilin, Peoples R China.;Northeast Normal Univ, Natl & Local United Engn Lab Power Battery, Changchun 130024, Jilin, Peoples R China..
    Di Marco, Igor
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ni, Lei
    Beihua Univ, Coll Chem & Biol, Jilin 132013, Jilin, Peoples R China..
    Tang, Shuwei
    Northeast Normal Univ, Inst Funct Mat, Fac Chem, Changchun 130024, Jilin, Peoples R China.;Northeast Normal Univ, Natl & Local United Engn Lab Power Battery, Changchun 130024, Jilin, Peoples R China..
    Zhang, Jingping
    Northeast Normal Univ, Inst Funct Mat, Fac Chem, Changchun 130024, Jilin, Peoples R China..
    Understanding the electrochemical properties of A(2)MSiO(4) (A = Li and Na; M = Fe, Mn, Co and Ni) and the Na doping effect on Li2MSiO4 from first-principles calculations2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 44, p. 17455-17463Article in journal (Refereed)
    Abstract [en]

    To explore the feasibility of regarding silicate materials as sustainable cathode materials for rechargeable Na ion batteries, the voltage plateaus, cycling stabilities, electrical conductivities and ionic conductivities of Li2MSiO4 and Na2MSiO4 (M = Fe, Mn, Co and Ni) are investigated by first principles calculations. The calculated electrochemical performance of silicate materials gives reasonable explanations for the poor capacity retention of Li2MnSiO4 as well as the reason why Li2FeSiO4 and Li2CoSiO4 exchange only one Li ion per formula unit. In comparison with Na2MSiO4, Li2MSiO4 presents higher voltage and better cycling stability. However, Na2MSiO4 displays higher electrical and ionic conductivities. Moreover, Na2NiSiO4 also presents significant potential for application as a good cathode material for Na ion batteries, as it can deliver high voltage and reversibly exchange 1.5 Li ions per formula unit. Furthermore, to make full use of the advantages of Li2MSiO4 and Na2MSiO4, a Na doped Li1.5Na0.5MSiO4 system is explored as well. The results suggest that Na doping can improve the electronic and ionic conductivities of Li2MSiO4 materials and simultaneously maintain the voltage and cycling stability. Therefore, Na ion doping should be an effective methodology to improve the performance of Li2MSiO4 cathode materials.

  • 49.
    Linnell, Stephanie F.
    et al.
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland.;Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England..
    Kim, Eun Jeong
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland.;Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England..
    Choi, Yong-Seok
    Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England.;UCL, Dept Chem, 20 Gordon St, London WC1H 0AJ, England.;UCL, Thomas Young Ctr, Gower St, London WC1E 6BT, England..
    Hirsbrunner, Moritz
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Imada, Saki
    Kyoto Inst Technol, Fac Elect Engn & Elect, Sakyo Ku, Kyoto 6068585, Japan..
    Pramanik, Atin
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland..
    Cuesta, Aida Fuente
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland..
    Miller, David N.
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland..
    Fusco, Edoardo
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland..
    Bode, Bela E.
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland..
    Irvine, John T. S.
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland.;Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England..
    Duda, Laurent C.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Condensed Matter Physics of Energy Materials.
    Scanlon, David O.
    Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England.;UCL, Dept Chem, 20 Gordon St, London WC1H 0AJ, England.;UCL, Thomas Young Ctr, Gower St, London WC1E 6BT, England..
    Armstrong, A. Robert
    Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland.;Faraday Inst, Quad One,Harwell Sci & Innovat Campus, Didcot OX11 0RA, Oxon, England..
    Enhanced oxygen redox reversibility and capacity retention of titanium-substituted Na-4/7[1/7Ti1/7Mn5/7]O-2 in sodium-ion batteries2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 18, p. 9941-9953Article in journal (Refereed)
    Abstract [en]

    Anion redox reactions offer a means of enhancing the capacity of layered sodium transition metal oxide positive electrode materials. However, oxygen redox reactions typically show limited reversibility and irreversible structural changes upon cycling, resulting in rapid capacity loss. Here, the Ti-substituted Na-4/7[1/7Ti1/7Mn5/7]O-2 (where represents a transition metal vacancy) is presented as a positive electrode material for sodium-ion batteries. Na-4/7[1/7Ti1/7Mn5/7]O-2 delivers a reversible capacity of 167 mA h g(-1) after 25 cycles at 10 mA g(-1) within the voltage range of 1.6-4.4 V and presents enhanced stability compared with Na-4/7[Mn-1/7(6/7)]O-2 over the voltage range 3.0-4.4 V. The structural and electronic structural changes of this Ti4+ substituted phase are investigated by powder X-ray diffraction, X-ray absorption spectroscopy, electron paramagnetic resonance and Raman spectroscopy, supported by density functional theory calculations. These results show that the Na-4/7[Mn-1/7(6/7)]O-2 structure is maintained between 3.0 and 4.4 V, and the presence of TiO6 octahedra in Na-4/7[1/7Ti1/7Mn5/7]O-2 relieves structural distortions from Jahn-Teller distorted Mn3+O6 between 1.6 and 4.4 V. Furthermore, Ti4+ substitution stabilises the adjacent O 2p orbitals and raises the ionicity of the Mn-O bonds, increasing the operating potential of Na-4/7[1/7Ti1/7Mn5/7]O-2. Thereby providing evidence that the improved electrochemical performance of Na-4/7[1/7Ti1/7Mn5/7]O-2 can be attributed to Ti4+ substitution. This work provides insight and strategies for improving the structural stability and electrochemical performance of sodium layered oxides.

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  • 50.
    Liu, Aijie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Tai, Cheuk-Wai
    Stockholm Univ, Arrhenius Lab, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Hola, Katerina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Tian, Haining
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hollow polymer dots: nature-mimicking architecture for efficient photocatalytic hydrogen evolution reaction2019In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 9, p. 4797-4803Article in journal (Refereed)
    Abstract [en]

    Mimicking nature is always beneficial for improving the performance of artificial systems. Artificial photosynthesis for hydrogen production is one of the examples, where we can derive significant inspiration from nature. In this study, polymer dots (Pdots) prepared using photoactive polymer PFODTBT and amphiphilic co-polymer under ultra-sonication exhibited a hollow structure mimicking a photosynthetic bacterial, which was highly beneficial for hydrogen evolution. A systematic study of this structure showed that the polymer shell acts as a biological membrane that maintains a slightly higher pH inside the cavity (pH 0.4) compared to the bulk solution. More importantly, a fast proton diffusion across the porous polymer shell was detected. The photocatalytic activity of hollow nanostructure shows 50 times enhancement of initial hydrogen evolution reaction (HER) rate as compared to solid nanoparticles. Further optimization of the photocatalytic performance was achieved by verifying the decrease in Pdots size from 90 nm to 50 nm, showing a significant increase in the photocatalytic performance of the system. This study reveals nature-mimicking hollow Pdots with porous shells as can be a type of promising photocatalysts in the application of solar energy conversion and storage.

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