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Edvinsson, Tomas, ProfessorORCID iD iconorcid.org/0000-0003-2759-7356
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Publications (10 of 178) Show all publications
Dürr, R. N., Maltoni, P., Feng, S., Ghorai, S., Ström, P., Tai, C.-W., . . . Edvinsson, T. (2024). Clearing Up Discrepancies in 2D and 3D Nickel Molybdate Hydrate Structures. Inorganic Chemistry, 63(5)
Open this publication in new window or tab >>Clearing Up Discrepancies in 2D and 3D Nickel Molybdate Hydrate Structures
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2024 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 63, no 5Article in journal (Refereed) Published
Abstract [en]

When electrocatalysts are prepared, modification of the morphology is a common strategy to enhance their electrocatalytic performance. In this work, we have examined and characterized nanorods (3D) and nanosheets (2D) of nickel molybdate hydrates, which previously have been treated as the same material with just a variation in morphology. We thoroughly investigated the materials and report that they contain fundamentally different compounds with different crystal structures, chemical compositions, and chemical stabilities. The 3D nanorod structure exhibits the chemical formula NiMoO4·0.6H2O and crystallizes in a triclinic system, whereas the 2D nanosheet structures can be rationalized with Ni3MoO5–0.5x(OH)x·(2.3 – 0.5x)H2O, with a mixed valence of both Ni and Mo, which enables a layered crystal structure. The difference in structure and composition is supported by X-ray photoelectron spectroscopy, ion beam analysis, thermogravimetric analysis, X-ray diffraction, electron diffraction, infrared spectroscopy, Raman spectroscopy, and magnetic measurements. The previously proposed crystal structure for the nickel molybdate hydrate nanorods from the literature needs to be reconsidered and is here refined by ab initio molecular dynamics on a quantum mechanical level using density functional theory calculations to reproduce the experimental findings. Because the material is frequently studied as an electrocatalyst or catalyst precursor and both structures can appear in the same synthesis, a clear distinction between the two compounds is necessary to assess the underlying structure-to-function relationship and targeted electrocatalytic properties.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
Keywords
nickel molybdate hydrate; nanorods, nanosheets layered nickel molybdate, α-NiMoO4, molybdenum leaching, Raman spectroscopy
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-476769 (URN)10.1021/acs.inorgchem.3c03261 (DOI)001158182800001 ()38242537 (PubMedID)
Funder
EU, Horizon 2020, 765376
Available from: 2022-06-13 Created: 2022-06-13 Last updated: 2024-03-01Bibliographically approved
Sun, W., Ahmed, T., Elbouazzaoui, K., Edvinsson, T., Zheng, Y. & Zhu, J. (2024). Facile fabrication of AgBr/HCCN hybrids with Z-scheme heterojunction for efficient photocatalytic hydrogen evolution. Applied Surface Science, 651, Article ID 159292.
Open this publication in new window or tab >>Facile fabrication of AgBr/HCCN hybrids with Z-scheme heterojunction for efficient photocatalytic hydrogen evolution
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2024 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 651, article id 159292Article in journal (Refereed) Published
Abstract [en]

Constructing a Z-scheme heterojunction with enhanced photocatalytic hydrogen evolution for graphitic carbon nitride-based (g-C3N4) composites is challenging because integrating g-C3N4 with other semiconductors, without specific band structure design, typically results in type I or type II heterojunctions. These heterojunctions have lower redox ability and limited enhancement in photocatalysis. Herein, we select highly crystalline carbon nitride (HCCN) as a proof-of-concept substrate. For the first time, we develop a AgBr nanosphere/HCCN composite photocatalyst that features an all -solid -state direct Z-scheme heterojunction for visible-light photocatalytic hydrogen evolution. The electron transfer mechanism is initially studied from the band structures and Fermi levels of HCCN and AgBr. It is subsequently confirmed by X-ray photoelectron spectroscopy (XPS), and electron microscopy. The close heterojunction contact and the built-in electron field of the Z-scheme heterojunction promote the migration and separation of photogenerated electrons and holes in the composite photocatalyst. Due to the redistribution of charge carriers, the photocatalyst shows superior redox capability and a markedly enhanced hydrogen evolution performance compared to its individual components. Combining all the advantages, AgBr nanosphere/HCCN reached an apparent quantum efficiency (AQE) of 6 % under the illumination of 410 nm, which is 4 times higher than that of the single HCCN component.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Highly crystalline carbon nitride, AgBr nanosphere, Z-scheme heterojunction, Photocatalysis, Hydrogen production
National Category
Physical Chemistry Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-522891 (URN)10.1016/j.apsusc.2024.159292 (DOI)001152746800001 ()
Funder
Swedish Energy Agency, 46641-1Olle Engkvists stiftelse, SOEB-2015/167
Available from: 2024-02-12 Created: 2024-02-12 Last updated: 2024-02-12Bibliographically approved
Spinelli, G., Morritt, G. H., Pavone, M., Probert, M. R., Waddel, P. G., Edvinsson, T., . . . Freitag, M. (2023). Conductivity in Thin Films of Transition Metal Coordination Complexes. ACS Applied Energy Materials, 6(4), 2122-2127
Open this publication in new window or tab >>Conductivity in Thin Films of Transition Metal Coordination Complexes
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2023 (English)In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 6, no 4, p. 2122-2127Article in journal (Refereed) Published
Abstract [en]

Two coordination complexes have been made by combining the dithiolene complexes [M(mnt)(2)](2-) (mnt = maleonitriledithiolate; M = Ni2+ or Cu2+) as anion, with the copper(II) coordination complex [Cu(Stetra)] (Stetra = 6,6 ' - bis(4,5-dihydrothiazol-2-yl)-2,2 ' -bipyri-dine) as cation. The variation of the metal centers leads to a dramatic change in the conductivity of the materials, with the M = Cu2+ variant (Cu-Cu) displaying semiconductor behavior with a conductivity of approximately 2.5 x 10(-8) S cm(-1), while the M = Ni2+ variant (Ni-Cu) displayed no observable conductivity. Computational studies found Cu-Cu enables a minimization of reorganization energy losses and, as a result, a lower barrier to the charge transfer process, resulting in the reported higher conductivity.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
Keywords
charge transfer, electrical conductivity, energy materials, coordination complexes, copper complexes, charge transfer materials, salts
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-512594 (URN)10.1021/acsaem.2c02999 (DOI)000932415500001 ()36875350 (PubMedID)
Available from: 2023-09-27 Created: 2023-09-27 Last updated: 2024-01-29Bibliographically approved
Valvo, M., Thyr, J. & Edvinsson, T. (2023). Defect-Induced Raman Scattering in Cu2O Nanostructures and Their Photocatalytic Performance. ChemElectroChem, 10(22), Article ID e202300376.
Open this publication in new window or tab >>Defect-Induced Raman Scattering in Cu2O Nanostructures and Their Photocatalytic Performance
2023 (English)In: ChemElectroChem, E-ISSN 2196-0216, Vol. 10, no 22, article id e202300376Article in journal (Refereed) Published
Abstract [en]

Advanced oxidation processes using photogenerated charges in semiconductors constitute an approach to reduce and oxidize pollutants, with an efficiency that depends on the photo physics and defect chemistry of the photocatalyst. In this study, 2D Cu2O coatings on flat copper metal and on 3D copper nanopillars are created via low-temperature oxidation and compared. The structures are characterized by X-ray diffraction, Raman spectroscopy, and electron microscopy. The thickest surface oxide layers on the 3D structures show outgrowth of high-aspect ratio CuO nano-needles through the Cu2O layer, rationalized through a field-induced copper ion diffusion mechanism. Raman scattering provides details about both the specific copper oxide phase present and the type and extent of defects, with a resolution spanning from hundreds of nanometers to micrometers. We show that defects in Cu2O induce Raman activity in several of its modes that are purely IR-active or optically silent in pristine Cu2O. The experimental results are corroborated by linear response density functional theory (DFT) calculations for full vibrational mode analysis. The Cu-supported 2D copper oxide systems exhibit effective photocatalytic performance at quite low probe pollution concentration (10 mu M), while the 3D nanopillar structures enhance the photocatalytic efficiency by around 30 % compared to their planar counterpart under these conditions.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2023
Keywords
copper oxide, defect-induced Raman scattering, density functional theory, electrodeposition, photocatalysis
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-522488 (URN)10.1002/celc.202300376 (DOI)001085621000001 ()
Funder
Swedish Research Council, 2019-00207Swedish Research Council Formas, 2016-00908Swedish Research Council, 2019-05591
Note

De två första författarna delar förstaförfattarskapet.

Available from: 2024-02-07 Created: 2024-02-07 Last updated: 2024-02-07Bibliographically approved
Thyr, J. & Edvinsson, T. (2023). Evading the Illusions: Identification of False Peaks in Micro-Raman Spectroscopy and Guidelines for Scientific Best Practice. Angewandte Chemie International Edition, 62(43), Article ID e202219047.
Open this publication in new window or tab >>Evading the Illusions: Identification of False Peaks in Micro-Raman Spectroscopy and Guidelines for Scientific Best Practice
2023 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 62, no 43, article id e202219047Article, review/survey (Refereed) Published
Abstract [en]

Micro-Raman spectroscopy is an important analytical tool in a large variety of science disciplines. The technique is suitable for both identification of chemical bonds and studying more detailed phenomena like molecular interactions, material strain, crystallinity, defects, and bond formations. Raman scattering has one major weakness however: it is a very low probability process. The weak signals require very sensitive detection systems, which leads to a high probability of picking up signals from origins other than the sample. This complicates the analysis of the results and increases the risk of misinterpreting data. This work provides an overview of the sources of spurious signals occurring in Raman spectra, including photoluminescence, cosmic rays, stray light, artefacts caused by spectrometer components, and signals from other compounds in or surrounding the sample. The origins of these false Raman peaks are explained and means to identify and counteract them are provided. Raman spectroscopy is a great analysis tool but the spectra are sometimes difficult to interpret due to the occurrence of spectral artefacts. This paper dives into the details of many spurious signals and spectral artefacts that occur in Raman spectra, explains their origin, and provides the tools to identify and avoid them.

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Keywords
Measurement Protocol, Raman Spectroscopy, Scientific Best Practice, Spectral Artefacts, Unintended Raman Signal
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-521084 (URN)10.1002/anie.202219047 (DOI)001064601200001 ()37702274 (PubMedID)
Funder
Swedish Research Council, 2019-05591
Available from: 2024-01-18 Created: 2024-01-18 Last updated: 2024-01-18Bibliographically approved
Araujo, R. B., Bayrak Pehlivan, I. & Edvinsson, T. (2023). High-entropy alloy catalysts: Fundamental aspects, promises towards electrochemical NH3 production, and lessons to learn from deep neural networks. Nano Energy, 105, Article ID 108027.
Open this publication in new window or tab >>High-entropy alloy catalysts: Fundamental aspects, promises towards electrochemical NH3 production, and lessons to learn from deep neural networks
2023 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 105, article id 108027Article in journal (Refereed) Published
Abstract [en]

A computational approach to judiciously predict high-entropy alloys (HEAs) as an efficient and sustainable material class for the electrochemical reduction of nitrogen is here presented. The approach employs density functional theory (DFT), adsorption energies of N atoms and N2 molecules as descriptors of the catalytic activity and deep neural networks. A probabilistic approach to quantifying the activity of HEA catalysts for nitrogen reduction reaction (NRR) is described, where catalyst elements and concentration are optimized to increase the probability of specific atomic arrangements on the surfaces. The approach provides key features for the effective filtering of HEA candidates without the need for time-consuming calculations. The relationships between activity and selectivity, which correlate with the averaged valence electron concentration and averaged electronegativity of the reference HEA catalyst, are analyzed in terms of sufficient interaction for sustained reactions and, at the same time, for the release of the active site. As a result, a complete list of 3000 HEAs consisting of quinary components of the elements Mo, Cr, Mn, Fe, Co, Ni, Cu, and Zn are reported together with their metrics to rank them from the most likely to the least likely active catalysts for NRR in gas diffusion electrodes, or for the case where non-aqueous electrolytes are utilized to suppress the competing hydrogen evolution reaction. Moreover, the energetic landscape of the electrochemical NRR transformations are computed and compared to the case of Fe. The study also analyses and discusses how the results would translate to liquid-solid reactions in aqueous electrochemical cells, further affected by changes in properties upon hydroxylation, oxygen, hydrogen, and water coverages.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
High-entropy alloys, Electrocatalytic nitrogen reduction, Scaling-relations, Machine learning, Deep neural networks
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:uu:diva-492684 (URN)10.1016/j.nanoen.2022.108027 (DOI)000898668000003 ()
Funder
Swedish Research Council, 2019-05591EU, Horizon 2020, 101006941Swedish National Infrastructure for Computing (SNIC), 2021/5-282
Available from: 2023-01-10 Created: 2023-01-10 Last updated: 2023-01-10Bibliographically approved
Araujo, R. & Edvinsson, T. (2023). N-2 adsorption on high-entropy alloy surfaces: unveiling the role of local environments. Journal of Materials Chemistry A, 11(24), 12973-12983
Open this publication in new window or tab >>N-2 adsorption on high-entropy alloy surfaces: unveiling the role of local environments
2023 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 11, no 24, p. 12973-12983Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Chemical Sciences
Research subject
Chemistry with specialization in Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-510960 (URN)10.1039/d2ta09348k (DOI)000959402300001 ()
Funder
Swedish National Infrastructure for Computing (SNIC), SNIC 2021/5-282Swedish Research Council, 2019-05591VinnovaSwedish Research Council
Available from: 2023-09-06 Created: 2023-09-06 Last updated: 2023-09-06Bibliographically approved
Jacobsson, J., Hultqvist, A., Garcia-Fernandez, A., Anand, A., Al-Ashouri, A., Hagfeldt, A., . . . Unger, E. (2022). An open-access database and analysis tool for perovskite solar cells based on the FAIR data principles. Nature Energy, 7(1), 107-115
Open this publication in new window or tab >>An open-access database and analysis tool for perovskite solar cells based on the FAIR data principles
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2022 (English)In: Nature Energy, E-ISSN 2058-7546, Vol. 7, no 1, p. 107-115Article in journal (Refereed) Published
Abstract [en]

Making large datasets findable, accessible, interoperable and reusable could accelerate technology development. Now, Jacobsson et al. present an approach to build an open-access database and analysis tool for perovskite solar cells. Large datasets are now ubiquitous as technology enables higher-throughput experiments, but rarely can a research field truly benefit from the research data generated due to inconsistent formatting, undocumented storage or improper dissemination. Here we extract all the meaningful device data from peer-reviewed papers on metal-halide perovskite solar cells published so far and make them available in a database. We collect data from over 42,400 photovoltaic devices with up to 100 parameters per device. We then develop open-source and accessible procedures to analyse the data, providing examples of insights that can be gleaned from the analysis of a large dataset. The database, graphics and analysis tools are made available to the community and will continue to evolve as an open-source initiative. This approach of extensively capturing the progress of an entire field, including sorting, interactive exploration and graphical representation of the data, will be applicable to many fields in materials science, engineering and biosciences.

Place, publisher, year, edition, pages
NATURE PORTFOLIO, 2022
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-470068 (URN)10.1038/s41560-021-00941-3 (DOI)000729687900004 ()
Funder
EU, Horizon 2020, 841386EU, Horizon 2020, 795079EU, Horizon 2020, 840751Swedish Research Council, 2019-05591Swedish Energy Agency, 2020-005194
Available from: 2022-04-05 Created: 2022-04-05 Last updated: 2022-08-22Bibliographically approved
Michaels, H., Golomb, M. J., Kim, B. J., Edvinsson, T., Cucinotta, F., Waddell, P. G., . . . Freitag, M. (2022). Copper coordination polymers with selective hole conductivity. Journal of Materials Chemistry A, 10(17), 9582-9591
Open this publication in new window or tab >>Copper coordination polymers with selective hole conductivity
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2022 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 17, p. 9582-9591Article in journal (Refereed) Published
Abstract [en]

Emerging technologies in solar energy will be critical in enabling worldwide society in overcoming the present energy challenges and reaching carbon net zero. Inefficient and unstable charge transport materials limit the current emerging energy conversion and storage technologies. Low-dimensional coordination polymers represent an alternative, unprecedented class of charge transport materials, comprised of molecular building blocks. Here, we provide a comprehensive study of mixed-valence coordination polymers from an analysis of the charge transport mechanism to their implementation as hole-conducting layers. Cu-II dithiocarbamate complexes afford morphology control of 1D polymer chains linked by (CuI2X2) copper halide rhombi. Concerted theoretical and experimental efforts identified the charge transport mechanism in the transition to band-like transport with a modeled effective hole mass of 6m(e). The iodide-bridged coordination polymer showed an excellent conductivity of 1 mS cm(-1) and a hole mobility of 5.8 10(-4) cm(2) (V s)(-1) at room temperature. Nanosecond selective hole injection into coordination polymer thin films was captured by nanosecond photoluminescence of halide perovskite films. Coordination polymers constitute a sustainable, tunable alternative to the current standard of heavily doped organic hole conductors.

National Category
Condensed Matter Physics Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-484838 (URN)10.1039/d2ta00267a (DOI)000775100700001 ()
Funder
Swedish Energy Agency, 42037-1Swedish Energy Agency, 43294-1StandUp
Available from: 2022-09-16 Created: 2022-09-16 Last updated: 2022-09-16Bibliographically approved
Thyr, J., Valvo, M. & Edvinsson, T. (2022). Cu2O-Coated Copper Nanopillars For Photocatalytic Water Cleaning. In: : . Paper presented at 5th International Conference on Applied Surface Science.
Open this publication in new window or tab >>Cu2O-Coated Copper Nanopillars For Photocatalytic Water Cleaning
2022 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Water pollution is a severe problem in many parts of the world. In developed countries the increased use of chemicals and urban densification has started to cause stress of previously well-functioning water systems. Advanced oxidation processes (AOPs), is a promising method for degradation of artificial organic pollutants, which are challenging to remove by conventional water treatment techniques. In AOPs hydroxyl radicals (OH•) and reactive oxygen species (O2- and O22-) which are strongly oxidizing species are generated and these subsequently react with and degrade the pollutants. To use nanostructures which are optically active in the visible part of the spectrum is attractive because it both creates a large surface area, promoting surface interface reactions, as well as enables the utilization of a large part of the solar spectrum. In this study flat copper surfaces and 3D nanostructured copper pillars are utilized as base structures. These are subjected to thermal oxidation at low temperature, for a controlled amount of time, creating thin copper oxide layers which makes them photoactive in the visible range. The formed copper oxide and its growth is analysed with SEM, XRD and Raman spectroscopy, and show the formation of Cu2O with a slight incorporation of CuO for the thickest oxide layers. Formation of CuO nano needles, protruding from the Cu2O layer, were observed in the SEM imaging. The photocatalytic performance was tested by degradation of methylene blue in aqueous solution and all of the tested systems showed quite effective performance. The highest degradation rate was seen for copper nanopillars annealed for 4 or 8 min, which exhibited 34% faster degradation than the oxidized flat sample. The study shows that simple and inexpensive thermal oxidation processes can be used to create efficient photoactive Cu2O catalysts even on semi-flat surfaces, and that nanostructuring increases the degradation rates.

Keywords
Cu2O, photocatalysis, water cleaning
National Category
Materials Chemistry Materials Engineering
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-479066 (URN)
Conference
5th International Conference on Applied Surface Science
Funder
Swedish Research Council Formas, FORMAS-2016-00908Uppsala University
Available from: 2022-06-28 Created: 2022-06-28 Last updated: 2022-06-28
Projects
Towards Improved Understanding of Surface Properties during Photocatalytic Water Splitting [2015-03814_VR]; Uppsala UniversitySuper Absorbing Pyrite Layers for Ultrathin Solar Cells [P44648-1_Energi]; Uppsala UniversityIon-Displacement and Defect Physics in Metal Halide Perovskite Solar Cell Materials [2019-05591_VR]; Uppsala UniversityThinnest and highly resilient electrodes for safe flexible electronic systems [2023-01607_Formas]; Uppsala UniversitySuppression of Thermal Losses in Emerging Quantum Materials [2023-05244_VR]; Uppsala University
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-2759-7356

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