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  • 1. Aartsen, M. G.
    et al.
    Ackermann, M.
    Adams, J.
    Aguilar, J. A.
    Ahlers, M.
    Ahrens, M.
    Altmann, D.
    Anderson, T.
    Arguelles, C.
    Arlen, T. C.
    Auffenberg, J.
    Bai, X.
    Barwick, S. W.
    Baum, V.
    Beatty, J. J.
    Tjus, J. Becker
    Becker, K. -H
    BenZvi, S.
    Berghaus, P.
    Berley, D.
    Bernardini, E.
    Bernhard, A.
    Besson, D. Z.
    Binder, G.
    Bindig, D.
    Bissok, M.
    Blaufuss, E.
    Blumenthal, J.
    Boersma, David J.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Bohm, C.
    Bos, F.
    Bose, D.
    Boeser, S.
    Botner, Olga
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Brayeur, L.
    Bretz, H. P.
    Brown, A. M.
    Casey, J.
    Casier, M.
    Cheung, E.
    Chirkin, D.
    Christov, A.
    Christy, B.
    Clark, K.
    Classen, L.
    Clevermann, F.
    Coenders, S.
    Cowen, D. F.
    Silva, A. H. Cruz
    Danninger, M.
    Daughhetee, J.
    Davis, J. C.
    Day, M.
    De Andre, J. P. A. M.
    DeClercq, C.
    De Ridder, S.
    Desiati, P.
    De Vries, K. D.
    Dewith, M.
    DeYoung, T.
    Diaz-Velez, J. C.
    Dunkman, M.
    Eagan, R.
    Eberhardt, B.
    Eichmann, B.
    Eisch, J.
    Euler, Sebastian
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Evenson, P. A.
    Fadiran, O.
    Fazely, A. R.
    Fedynitch, A.
    Feintzeig, J.
    Felde, J.
    Feusels, T.
    Filimonov, K.
    Finley, C.
    Fischer-Wasels, T.
    Flis, S.
    Franckowiak, A.
    Frantzen, K.
    Fuchs, T.
    Gaisser, T. K.
    Gaior, R.
    Gallagher, J.
    Gerhardt, L.
    Gier, D.
    Gladstone, L.
    Glusenkamp, T.
    Goldschmidt, A.
    Golup, G.
    Gonzalez, J. G.
    Goodman, J. A.
    Gora, D.
    Grant, D.
    Gretskov, P.
    Groh, J. C.
    Gro, A.
    Ha, C.
    Haack, C.
    Ismail, A. Haj
    Hallen, P.
    Hallgren, Allan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Halzen, F.
    Hanson, K.
    Hebecker, D.
    Heereman, D.
    Heinen, D.
    Helbing, K.
    Hellauer, R.
    Hellwig, D.
    Hickford, S.
    Hill, G. C.
    Hoffman, K. D.
    Hoffmann, R.
    Homeier, A.
    Hoshina, K.
    Huang, F.
    Huelsnitz, W.
    Hulth, P. O.
    Hultqvist, K.
    Hussain, S.
    Ishihara, A.
    Jacobi, E.
    Jacobsen, J.
    Jagielski, K.
    Japaridze, G. S.
    Jero, K.
    Jlelati, O.
    Jurkovic, M.
    Kaminsky, B.
    Kappes, A.
    Karg, T.
    Karle, A.
    Kauer, M.
    Keivani, A.
    Kelley, J. L.
    Kheirandish, A.
    Kiryluk, J.
    Klaes, J.
    Klein, S. R.
    Koehne, J. H.
    Kohnen, G.
    Kolanoski, H.
    Koob, A.
    Koepke, L.
    Kopper, C.
    Kopper, S.
    Koskinen, D. J.
    Kowalski, M.
    Kriesten, A.
    Krings, K.
    Kroll, G.
    Kroll, M.
    Kunnen, J.
    Kurahashi, N.
    Kuwabara, T.
    Labare, M.
    Larsen, D. T.
    Larson, M. J.
    Lesiak-Bzdak, M.
    Leuermann, M.
    Leute, J.
    Luenemann, J.
    Madsen, J.
    Maggi, G.
    Maruyama, R.
    Mase, K.
    Matis, H. S.
    Maunu, R.
    McNally, F.
    Meagher, K.
    Medici, M.
    Meli, A.
    Meures, T.
    Miarecki, S.
    Middell, E.
    Middlemas, E.
    Milke, N.
    Miller, J.
    Mohrmann, L.
    Montaruli, T.
    Morse, R.
    Nahnhauer, R.
    Naumann, U.
    Niederhausen, H.
    Nowicki, S. C.
    Nygren, D. R.
    Obertacke, A.
    Odrowski, S.
    Olivas, A.
    Omairat, A.
    O'Murchadha, A.
    Palczewski, T.
    Paul, L.
    Penek, Oe.
    Pepper, J. A.
    Perez De Los Heros, Carlos
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Pfendner, C.
    Pieloth, D.
    Pinat, E.
    Posselt, J.
    Price, P. B.
    Przybylski, G. T.
    Puetz, J.
    Quinnan, M.
    Raedel, L.
    Rameez, M.
    Rawlins, K.
    Redl, P.
    Rees, I.
    Reimann, R.
    Relich, M.
    Resconi, E.
    Rhode, W.
    Richman, M.
    Riedel, B.
    Robertson, S.
    Rodrigues, J. P.
    Rongen, M.
    Rott, C.
    Ruhe, T.
    Ruzybayev, B.
    Ryckbosch, D.
    Saba, S. M.
    Sander, H. -G
    Sandroos, J.
    Santander, M.
    Sarkar, S.
    Schatto, K.
    Scheriau, F.
    Schmidt, T.
    Schmitz, M.
    Schoenen, S.
    Schoeneberg, S.
    Schoenwald, A.
    Schukraft, A.
    Schulte, L.
    Schulz, O.
    Seckel, D.
    Sestayo, Y.
    Seunarine, S.
    Shanidze, R.
    Smith, M. W. E.
    Soldin, D.
    Spiczak, G. M.
    Spiering, C.
    Stamatikos, M.
    Stanev, T.
    Stanisha, N. A.
    Stasik, A.
    Stezelberger, T.
    Stokstad, R. G.
    Stoessl, A.
    Strahler, E. A.
    Ström, Rickard
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Strotjohann, N. L.
    Sullivan, G. W.
    Taavola, Henric
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Taboada, I.
    Tamburro, A.
    Tepe, A.
    Ter-Antonyan, S.
    Terliuk, A.
    Tesic, G.
    Tilav, S.
    Toale, P. A.
    Tobin, M. N.
    Tosi, D.
    Tselengidou, M.
    Unger, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Usner, M.
    Vallecorsa, S.
    Van Eijndhoven, N.
    Vandenbroucke, J.
    Van Santen, J.
    Vehring, M.
    Voge, M.
    Vraeghe, M.
    Walck, C.
    Wallraff, M.
    Weaver, Ch.
    Wellons, M.
    Wendt, C.
    Westerhoff, S.
    Whelan, B. J.
    Whitehorn, N.
    Wichary, C.
    Wiebe, K.
    Wiebusch, C. H.
    Williams, D. R.
    Wissing, H.
    Wolf, M.
    Wood, T. R.
    Woschnagg, K.
    Xu, D. L.
    Xu, X. W.
    Yanez, J. P.
    Yodh, G.
    Yoshida, S.
    Zarzhitsky, P.
    Ziemann, J.
    Zierke, S.
    Zoll, M.
    Morik, K.
    Development of a general analysis and unfolding scheme and its application to measure the energy spectrum of atmospheric neutrinos with IceCube2015In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 75, no 3, article id 116Article in journal (Refereed)
    Abstract [en]

    We present the development and application of a generic analysis scheme for the measurement of neutrino spectra with the IceCube detector. This scheme is based on regularized unfolding, preceded by an event selection which uses a Minimum Redundancy Maximum Relevance algorithm to select the relevant variables and a random forest for the classification of events. The analysis has been developed using IceCube data from the 59-string configuration of the detector. 27,771 neutrino candidates were detected in 346 days of livetime. A rejection of 99.9999 % of the atmospheric muon background is achieved. The energy spectrum of the atmospheric neutrino flux is obtained using the TRUEE unfolding program. The unfolded spectrum of atmospheric muon neutrinos covers an energy range from 100 GeV to 1 PeV. Compared to the previous measurement using the detector in the 40-string configuration, the analysis presented here, extends the upper end of the atmospheric neutrino spectrum by more than a factor of two, reaching an energy region that has not been previously accessed by spectral measurements.

  • 2.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Huang, Zhehao
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Zheng, Haoquan
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Inorgan & Struct Chem, SE-10691 Stockholm, Sweden;Stockholm Univ, Berzelii Ctr EXSELENT Porous Mat, Dept Mat & Environm Chem, SE-10691 Stockholm, Sweden.
    A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules2017In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 56, no 15, p. 9139-9146Article in journal (Refereed)
    Abstract [en]

    A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic, imidazolate framework ZIF-8, nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were, tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim): Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300-2500 m(2)/g), and large pore Volatiles (0.5-1.0 cm(3)/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled Up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3-27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIP (dye@ZIF-67).

  • 3.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;Assiut Univ, Dept Chem, Assiut 71515, Egypt.
    Wilk-Kozubek, Magdalena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden;PORT Polish Ctr Technol Dev, Dept Nanotechnol, 147 Stablowicka St, PL-54066 Wroclaw, Poland.
    El-Zohry, Ahmed
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Gomez, Antonio Bermejo
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Valiente, Alejandro
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Martin-Matute, Belen
    Stockholm Univ, Dept Organ Chem, SE-10691 Stockholm, Sweden.
    Mudring, Anja-Verena
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Zou, Xiaodong
    Stockholm Univ, Dept Mat & Environm Chem, Berzelii Ctr EXSELENT Porous Mat, SE-10691 Stockholm, Sweden.
    Luminescence properties of a family of lanthanide metal-organic frameworks2019In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 279, p. 400-406Article in journal (Refereed)
    Abstract [en]

    Two isostructural series of lanthanide metal-organic frameworks denoted as SUMOF-7II (Ln) and SUMOF-7IIB (Ln) (Ln = La, Ce, Pr, Nd, Sm, Eu, and Gd) were synthesized using4,4',4 ''-(pyridine-2,4,6-triyl)tris(benzoic acid) (H(3)L2) and a mixture of H(3)L2 and 4,4',4 ''-(benzene-1,3,5-triyl)tris(benzoic acid) (H3BTB) as linkers, respectively. Both series were characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermal analysis (TGA), and photoluminescence spectroscopy. Photoluminescence measurements show that Eu-MOFs demonstrate a red emission while Pr- and Nd-MOFs display an emission in the near-infrared (NIR) range. On the other hand, La-, Ce-, Sm- and Gd-MOFs exhibit only a ligand-centered emission. The average luminescence lifetimes in the SUMOF-7IIB series are 1.3-1.4-fold longer than the corresponding ones in the SUMOF-7II series. SUMOF-7IIs show a good photo- and thermal stability. Altogether, the properties of SUMOF-7II and SUMOF-7IIB render them promising materials for applications including sensing, biosensing, and telecommunications.

  • 4.
    Abdellah, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt..
    El-Zohry, Ahmed M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Antila, Liisa J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Windle, Christopher D.
    Univ Cambridge, Dept Chem, Christian Doppler Lab Sustainable SynGas Chem, Lensfield Rd, Cambridge CB2 1EW, England..
    Reisner, Erwin
    Univ Cambridge, Dept Chem, Christian Doppler Lab Sustainable SynGas Chem, Lensfield Rd, Cambridge CB2 1EW, England..
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Time-Resolved IR Spectroscopy Reveals a. Mechanism with TiO2 as a Reversible Electron Acceptor in a TiO2-Re Catalyst System for CO2 Photoreduction2017In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 139, no 3, p. 1226-1232Article in journal (Refereed)
    Abstract [en]

    Attaching the phosphonated molecular catalyst [(ReBr)-Br-I(bpy)-(CO)(3)](0) to the wide-bandgap semiconductor TiO2 strongly enhances the rate of visible-light-driven reduction of CO2 to CO in dimethylformamide with triethanolamine (TEOA) as sacrificial electron donor. Herein, we show by transient mid-IR spectroscopy that the mechanism of catalyst photoreduction is initiated by ultrafast electron injection into TiO2, followed by rapid (ps-ns) and sequential two-electron oxidation of TEOA that is coordinated to the Re center. The injected electrons can be stored in the conduction band of TiO2 on an ms-s time scale, and we propose that they lead to further reduction of the Re catalyst and completion of the catalytic cycle. Thus, the excited Re catalyst gives away one electron and would eventually get three electrons back. The function of an electron reservoir would represent a role for TiO2 in photocatalytic CO2 reduction that has previously not been considered. We propose that the increase in photocatalytic activity upon heterogenization of the catalyst to TiO2 is due to the slow charge recombination and the high oxidative power of the Re-II species after electron injection as compared to the excited MLCT state of the unbound Re catalyst or when immobilized on ZrO2, which results in a more efficient reaction with TEOA.

  • 5.
    Abdellah, Mohamed
    et al.
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden.;South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt..
    Poulsen, Felipe
    Univ Copenhagen, Dept Chem, DK-2100 Copenhagen, Denmark..
    Zhu, Qiushi
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Zhu, Nan
    Tech Univ Denmark, Dept Chem, Kemitorvet Bldg 207, DK-2800 Lyngby, Denmark.;Dalian Univ Technol, Zhang Dayu Sch Chem, Dalian 116024, Peoples R China..
    Zidek, Karel
    Acad Sci Czech Republ, Inst Plasma Phys, Reg Ctr Special Opt & Optoelect Syst TOPTEC, Za Slovankou 1782-3, Prague 18200 8, Czech Republic..
    Chabera, Pavel
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Corti, Annamaria
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hansen, Thorsten
    Univ Copenhagen, Dept Chem, DK-2100 Copenhagen, Denmark..
    Chi, Qijin
    Tech Univ Denmark, Dept Chem, Kemitorvet Bldg 207, DK-2800 Lyngby, Denmark..
    Canton, Sophie E.
    DESY, Attosecond Sci Grp, Notkestr 85, D-22607 Hamburg, Germany.;ELI HU Nonprofit Ltd, ELI ALPS, Dugonics Ter 13, H-6720 Szeged, Hungary..
    Zheng, Kaibo
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden.;Qatar Univ, Coll Engn, Gas Proc Ctr, POB 2713, Doha, Qatar..
    Pullerits, Tonu
    Lund Univ, Div Chem Phys, Box 124, S-22100 Lund, Sweden.;Lund Univ, NanoLund, Box 124, S-22100 Lund, Sweden..
    Drastic difference between hole and electron injection through the gradient shell of CdxSeyZn1−xS1−y quantum dots2017In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 34, p. 12503-12508Article in journal (Refereed)
    Abstract [en]

    Ultrafast fluorescence spectroscopy was used to investigate the hole injection in CdxSeyZn1-xS1-y gradient core-shell quantum dot (CSQD) sensitized p-type NiO photocathodes. A series of CSQDs with a wide range of shell thicknesses was studied. Complementary photoelectrochemical cell measurements were carried out to confirm that the hole injection from the active core through the gradient shell to NiO takes place. The hole injection from the valence band of the QDs to NiO depends much less on the shell thickness when compared to the corresponding electron injection to n-type semiconductor (ZnO). We simulate the charge carrier tunneling through the potential barrier due to the gradient shell by numerically solving the Schrodinger equation. The details of the band alignment determining the potential barrier are obtained from X-ray spectroscopy measurements. The observed drastic differences between the hole and electron injection are consistent with a model where the hole effective mass decreases, while the gradient shell thickness increases.

  • 6.
    Abdellah, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. South Valley Univ, Qena Fac Sci, Dept Chem, Qena 83523, Egypt.
    Zhang, Shihuai
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Wang, Mei
    Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, State Key Lab Fine Chem, Dalian 116024, Peoples R China..
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Competitive Hole Transfer from CdSe Quantum Dots to Thiol Ligands in CdSe-Cobaloxime Sensitized NiO Films Used as Photocathodes for H-2 Evolution2017In: ACS Energy Letters, ISSN 2380-8195, Vol. 2, no 11, p. 2576-2580Article in journal (Refereed)
    Abstract [en]

    Quantum dot (QD) sensitized NiO photocathodes rely on efficient photoinduced hole injection into the NiO valence band. A system of a mesoporous NiO film co-sensitized with CdSe QDs and a molecular proton reduction catalyst was studied. While successful electron transfer from the excited QDs to the catalyst is observed, most of the photogenerated holes are instead quenched very rapidly (ps) by hole trapping at the surface thiols of the capping agent used as linker molecules. We confirmed our conclusion by first using a thiol free capping agent and second varying the thiol concentration on the QD's surface. The later resulted in faster hole trapping as the thiol concentration increased. We suggest that this hole trapping by the linker limits the H-2 yield for this photocathode in a device.

  • 7.
    Abrahamsson, Maria
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Becker, Hans-Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Microsecond (MLCT)-M-3 excited state lifetimes in bis-tridentate Ru(II)-complexes: significant reductions of non-radiative rate constants2017In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 46, no 39, p. 13314-13321Article in journal (Refereed)
    Abstract [en]

    In this paper we report the photophysical properties of a series of bis-tridentate Ru-II-complexes, based on the dqp-ligand (dqp = 2,6-di(quinolin-8-yl) pyridine), which display several microsecond long excited state lifetimes for triplet metal-to-ligand charge transfer ((MLCT)-M-3) at room temperature. Temperature dependence of the excited state lifetimes for [Ru(dqp)(2)](2+) and [Ru(dqp)(ttpy)](2+) (ttpy = 4'-tolyl-2,2': 6', 2 ''-terpyridine) is reported and radiative and non-radiative rate constants for the whole series are reported and discussed. We can confirm previous assumptions that the near-octahedricity of the bis-dqp complexes dramatically slows down activated decay at room temperature, as compared to most other and less long-lived bis-tridentate RuII-complexes, such as [Ru(tpy)(2)](2+) with tau = 0.25 ns at room temperature (tpy = 2,2': 6', 2 ''-terpyridine). Moreover, the direct non-radiative decay to the ground state is comparatively slow for similar to 700 nm room-temperature emission when considering the energy-gap law. Analysis of the 77 K emission spectra suggests that this effect is not primarily due to smaller excited state distortion than that for comparable complexes. Instead, an analysis of the photophysical parameters suggests a weaker singlet-triplet mixing in the MLCT state, which slows down both radiative and non-radiative decay.

  • 8. Achari, Muthuraaman Bhagavathi
    et al.
    Elumalai, Viswanathan
    Vlachopoulos, Nikolaos
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Safdari, Majid
    Gao, Jiajia
    Gardner, James M.
    Kloo, Lars
    A quasi-liquid polymer-based cobalt redox mediator electrolyte for dye-sensitized solar cells2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 40, p. 17419-17425Article in journal (Refereed)
    Abstract [en]

    Recently, cobalt redox electrolyte mediators have emerged as a promising alternative to the commonly used iodide/triiodide redox shuttle in dye-sensitized solar cells (DSCs). Here, we report the successful use of a new quasi-liquid, polymer-based electrolyte containing the Co3+/Co2+ redox mediator in 3-methoxy propionitrile solvent in order to overcome the limitations of high cell resistance, low diffusion coefficient and rapid recombination losses. The performance of the solar cells containing the polymer based electrolytes increased by a factor of 1.2 with respect to an analogous electrolyte without the polymer. The performances of the fabricated DSCs have been investigated in detail by photovoltaic, transient electron measurements, EIS, Raman and UV-vis spectroscopy. This approach offers an effective way to make high-performance and long-lasting DSCs.

  • 9. Adamska-Venkatesh, Agnieszka
    et al.
    Mirmohades, Mohammad
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Sommer, Constanze
    Reijerse, Edward
    Lubitz, Wolfgang
    Lomoth, Reiner
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Following [FeFe] Hydrogenase Active Site Intermediates by Flash Photolysis/Mid-IR ProbingManuscript (preprint) (Other academic)
  • 10.
    Aitola, Kerttu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Domanski, Konrad
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland..
    Correa-Baena, Juan-Pablo
    MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA..
    Sveinbjörnsson, Kári
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Saliba, Michael
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland..
    Abate, Antonio
    Univ Fribourg, Adolphe Merkle Inst, CH-1700 Fribourg, Switzerland..
    Graetzel, Michael
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland..
    Kauppinen, Esko
    Aalto Univ, Dept Appl Phys, POB 15100, Aalto 00076, Finland..
    Johansson, Erik M.J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Tress, Wolfgang
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photon & Interfaces, CH-1015 Lausanne, Switzerland..
    Hagfeldt, Anders
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    High Temperature-Stable Perovskite Solar Cell Based on Low-Cost Carbon Nanotube Hole Contact2017In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 29, no 17, article id 1606398Article in journal (Refereed)
    Abstract [en]

    Mixed ion perovskite solar cells (PSC) are manufactured with a metal-free hole contact based on press-transferred single-walled carbon nanotube (SWCNT) film infiltrated with 2,2,7,-7-tetrakis(N, N-di-p-methoxyphenylamine)-9,90-spirobifluorene (Spiro-OMeTAD). By means of maximum power point tracking, their stabilities are compared with those of standard PSCs employing spin-coated Spiro-OMeTAD and a thermally evaporated Au back contact, under full 1 sun illumination, at 60 degrees C, and in a N-2 atmosphere. During the 140 h experiment, the solar cells with the Au electrode experience a dramatic, irreversible efficiency loss, rendering them effectively nonoperational, whereas the SWCNT-contacted devices show only a small linear efficiency loss with an extrapolated lifetime of 580 h.

  • 11.
    Aitola, Kerttu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Halme, Janne
    Feldt, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Lohse, Peter
    Borghei, Maryam
    Kaskela, Antti
    Nasibulin, Albert G.
    Kauppinen, Esko I.
    Lund, Peter D.
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Highly catalytic carbon nanotube counter electrode on plastic for dye solar cells utilizing cobalt-based redox mediator2013In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 111, p. 206-209Article in journal (Refereed)
    Abstract [en]

    A flexible, slightly transparent and metal-free random network of single-walled carbon nanotubes (SWCNTs) on plain polyethylene terephthalate (PET) plastic substrate outperformed platinum on conductive glass and on plastic as the counter electrode (CE) of a dye solar cell employing a Co(II/III)tris(2,2'-bipyridyl) complex redox mediator in 3-methoxypropionitrile solvent. The CE charge-transfer resistance of the SWCNT film was 0.60 Omega cm(2), 4.0 Omega cm(2) for sputtered platinum on indium tin oxide-PET substrate and 1.7 Omega cm(2) for thermally deposited Pt on fluorine-doped tin oxide glass, respectively. The solar cell efficiencies were in the same range, thus proving that an entirely carbon-based SWCNT film on plastic is as good CE candidate for the Co electrolyte. (C) 2013 Elsevier Ltd. All rights reserved.

  • 12.
    Aitola, Kerttu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Sveinbjörnsson, Kári
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Correa-Baena, Juan-Pablo
    Ecole Polytech Fed Lausanne, Lab Photomol Sci, EPFL SB ISIC LSPM, CH G1 523,Chemin Alamb,Stn 6, CH-1015 Lausanne, Switzerland..
    Kaskela, Antti
    Aalto Univ, Sch Sci, Dept Appl Phys, POB 15100, FI-00076 Aalto, Finland..
    Abate, Antonio
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, EPFL SB ISIC LPI, CH G1 526,Stn 6, CH-1015 Lausanne, Switzerland..
    Tian, Ying
    Aalto Univ, Sch Sci, Dept Appl Phys, POB 15100, FI-00076 Aalto, Finland..
    Johansson, Erik M. J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Graetzel, Michael
    Ecole Polytech Fed Lausanne, Lab Photon & Interfaces, Inst Chem Sci & Engn, EPFL SB ISIC LPI, CH G1 526,Stn 6, CH-1015 Lausanne, Switzerland..
    Kauppinen, Esko I.
    Aalto Univ, Sch Sci, Dept Appl Phys, POB 15100, FI-00076 Aalto, Finland..
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Ecole Polytech Fed Lausanne, Lab Photomol Sci, EPFL SB ISIC LSPM, CH G1 523,Chemin Alamb,Stn 6, CH-1015 Lausanne, Switzerland..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Carbon nanotube-based hybrid hole-transporting material and selective contact for high efficiency perovskite solar cells2016In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 9, no 2, p. 461-466Article in journal (Refereed)
    Abstract [en]

    We demonstrate a high efficiency perovskite solar cell with a hybrid hole-transporting material-counter electrode based on a thin single-walled carbon nanotube (SWCNT) film and a drop-cast 2,2,7,-7-tetrakis(N, N-di-p-methoxyphenylamine)-9,90-spirobifluorene (Spiro-OMeTAD) hole-transporting material (HTM). The average efficiency of the solar cells was 13.6%, with the record cell yielding 15.5% efficiency. The efficiency of the reference solar cells with spin-coated Spiro-OMeTAD hole-transportingmaterials (HTMs) and an evaporated gold counter electrode was 17.7% (record 18.8%), that of the cells with only a SWCNT counter electrode (CE) without additional HTM was 9.1% (record 11%) and that of the cells with gold deposited directly on the perovskite layer was 5% (record 6.3%). Our results show that it is possible to manufacture high efficiency perovskite solar cells with thin film (thickness less than 1 mu m) completely carbon-based HTMCEs using industrially upscalable manufacturing methods, such as press-transferred CEs and drop-cast HTMs.

  • 13.
    Aitola, Kerttu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Zhang, Jinbao
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Vlachopoulos, Nick
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, SB ISIC LSPM, CH-1015 Lausanne, Switzerland..
    Halme, Janne
    Aalto Univ, Sch Sci, Dept Appl Phys, Aalto 00076, Finland..
    Kaskela, Antti
    Aalto Univ, Sch Sci, Dept Appl Phys, Aalto 00076, Finland..
    Nasibulin, Albert G.
    Aalto Univ, Sch Sci, Dept Appl Phys, Aalto 00076, Finland.;Skolkovo Inst Sci & Technol, Skolkovo, Russia..
    Kauppinen, Esko I.
    Aalto Univ, Sch Sci, Dept Appl Phys, Aalto 00076, Finland..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Carbon nanotube film replacing silver in high-efficiency solid-state dye solar cells employing polymer hole conductor2015In: Journal of Solid State Electrochemistry, ISSN 1432-8488, E-ISSN 1433-0768, Vol. 19, no 10, p. 3139-3144Article in journal (Refereed)
    Abstract [en]

    A semitransparent, flexible single-walled carbon nanotube (SWCNT) film was efficiently used in place of evaporated silver as the counter electrode of a poly(3,4-ethylenedioxythiophene) polymer-based solid-state dye solar cell (SSDSC): the solar-to-electrical energy conversion efficiency of the SWCNT-SSDSC was 4.8 % when it was 5.2 % for the Ag-SSDSC. The efficiency difference stemmed from a 0.1-V difference in the open-circuit voltage, whose reason was speculated to be related to the different recombination processes in the two types of SSDSCs.

  • 14.
    Aldehani, Mohammed
    et al.
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    Alzahrani, Faris
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    tSaoir, Meabh Nic An
    Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT7 1NN, Antrim, North Ireland..
    Fernandes, Daniel Luis Abreu
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Assabumrungrat, Suttichai
    Chulalongkorn Univ, Fac Engn, Dept Chem Engn, Ctr Excellence Catalysis & Catalyt React Engn, Bangkok, Thailand..
    Aiouache, Farid
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    Kinetics and reactive stripping modelling of hydrogen isotopic exchange of deuterated waters2016In: Chemical Engineering and Processing, ISSN 0255-2701, E-ISSN 1873-3204, Vol. 108, p. 58-73Article in journal (Refereed)
    Abstract [en]

    This work presents results of experimental kinetics and modelling of the isotopic exchange between hydrogen and water in a reactive stripping column for water dedeuteriation. The missing physical properties of deuterium and tritium isotopologues in hydrogen gas and water forms were predicted and validated using existing literature data. The kinetic model relevant to a styrene-divinyl-benzene copolymer-supported platinum catalyst was used for modelling, by Aspen plus modular package, impact of design parameters including temperature, total pressure, gas to liquid flowrate ratio, pressure drop and flow mixing, on the separation of deuterium and further the separation of tritium. The modelling by the rate-based non-equilibrium, including design correlations of model of mass and heat transfers, chemical kinetic constants, mass transfer coefficients and overall exchange rate constants, allowed access to separation trends in a good agreement with published data. The synergy between the rates of chemical isotopic exchange and gas/liquid mass transfer, and by inference the performance of reactive stripping, was particularly sensitive to high temperatures, low hydrogen flow rates, pressure drops and internals properties. Extension to tritium confirmed a slightly slower mass transport compared with deuterium leading to potentially under-estimated design features for detritiation processing when deuterium is used instead.

  • 15.
    Alzahrani, Faris
    et al.
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    Aldehani, Mohammed
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    Rusi, Hao
    Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT7 1NN, Antrim, North Ireland..
    McMaster, Michael
    Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT7 1NN, Antrim, North Ireland..
    Fernandes, Daniel Luis Abreu
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Assabumrungrat, Suttichai
    Chulalongkorn Univ, Ctr Excellence Catalysis & Catalyt React Engn, Dept Chem Engn, Bangkok 10330, Thailand..
    tSaoir, Meabh Nic An
    Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT7 1NN, Antrim, North Ireland..
    Aiouachet, Farid
    Univ Lancaster, Dept Engn, Lancaster LA1 4YW, England..
    Gas Flow Visualization in Low Aspect Ratio Packed Beds by Three-Dimensional Modeling and Near-Infrared Tomography2015In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 54, no 51, p. 12714-12729Article in journal (Refereed)
    Abstract [en]

    Nonuniform local flow inside randomly porous media of gas solid packed beds of low aspect ratios ranging from 1.5 to 5 was investigated by three-dimensional modeling and near-infrared tomography. These beds are known to demonstrate heterogeneous mixing and uneven distributions of mass and heat. The effects of the confining wall on flow dynamics were found nonlinear, particularly for aspect ratios lower than 3. High velocities were mainly observed in regions near the wall of aspect ratio value of 1.5 and those of values higher than 3, owing to high local porosities in these zones. Mass dispersion characterized both by experimental near-infrared imaging and by particle tracking showed discrepancies with literature models, particularly for aspect ratios lower than 3. Uncertainties were more significant with the radial dispersion due to bed size limits. Beyond this value, the wall affected more the axial dispersion, confirming the nonlinear impact of the wall on global hydrodynamics.

  • 16.
    Andersson Chronholm, Jannika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Andersson, Staffan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Studenters attityder och Förväntningar2015Conference paper (Refereed)
  • 17.
    Andersson, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Danielsson, Anna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Hussénius, Anita
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Gullberg, Annica
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Engström, Susanne
    KTH.
    Blomqvist, Martha
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Scantlebury, Kathryn
    University of Delaware.
    Hasse, Cathrine
    Aarhus universitet.
    In the borderland between academic disciplines and school science - feminist perspectives on science teacher education2016Conference paper (Refereed)
  • 18.
    Andersson, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Danielsson, Anna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Hussénius, Anita
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Gullberg, Annica
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Engström, Susanne
    Kungliga Tekniska Högskolan.
    Blomqvist, Martha
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Scantlebury, Kathryn
    University of Delaware.
    Hasse, Cathrine
    DPU - Danmarks institut for Pædagogik og Uddannelse.
    In the borderland between academic disciplines and school science – feminist perspectives on science teacher education.2016Conference paper (Refereed)
  • 19.
    Andersson, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Danielsson, Anna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education.
    Hussénius, Anita
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Gullberg, Annica
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Engström, Susanne
    KTH.
    Blomqvist, Martha
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Scantlebury, Kathryn
    University of Delaware.
    Hasse, Cathrine
    Aarhus universitet.
    Science faculty as teacher educators – a feminist perspective.2016Conference paper (Refereed)
  • 20.
    Andersson, Kristina
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Danielsson, Anna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Educational Sciences, Department of Education. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Hussénius, Anita
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Gullberg, Annica
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Engström, Susanne
    Kungliga Tekniska Högskolan.
    Blomqvist, Martha
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Scantlebury, Kathryn
    University of Delaware.
    Hasse, Cathrine
    DPU - Danmarks institut for Pædagogik og Uddannelse.
    Science faculty as teacher educators – a feminist perspective2016Conference paper (Refereed)
  • 21.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Andersson Chronholm, Jannika
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Student Expectations of Academic Teachers Contributions to their Learning2015Conference paper (Refereed)
    Abstract [en]

    Student responses to introduction of pedagogical initiatives, such as adoption of research-based educational practices, can be very influential on the future of such initiatives (National Research Council, 2012). To inform this type of introduction processes, we present results from an investigation on beginner student's expectations of how academic teachers will contribute to their learning.

    Enrolling students in science and technology were asked the following open question as part of a web-based survey: "How do you expect your teachers to contribute to your learning?" 553 of about 880 students in the surveyed population choose to respond. Their answers were coded and iteratively sorted in a grounded theory approach (Robson, 2011).

    The three most common themes found in the answers were providing lectures, answering questions and providing information and structure. 58% of the students focussed on information transfer from the teachers, whereas 27% focussed on pedagogical approaches and student centred practices. The remaining 15% were too vague to be classified. A small minority of the student described contributions to learning that could be expected from a teacher inspired by the scholarship of teaching and learning. Some themes show statistically significant differences depending on student background factors, such as gender, programme affiliation and parents education. As an example, students from non-academic families to a larger extent expect teachers to be accessible for providing support.

    Our findings provide valuable insights into expectations of teachers from a heterogeneous student population. They also have important implications for how to introduce and motivate research-based teaching approaches to the whole student population.

     

    References

    National Research Council (2012). Discipline-Based Educational Research: Understanding and Improving Learning in Undergraduate Science and Engineering. National Academy Press, Washington D. C., p. 180-181.

    Robson, C. (2011). Real world research: a resource for users of social research methods in applied settings. (pp. 146-150) Chichester: Wiley.

  • 22.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Andersson Chronholm, Jannika
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Larsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Jacobsson, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Jämföra och rangordna: studentaktiv undervisning2012In: Universitetspedagogisk utveckling och kvalitet: i praktiken!, 2012Conference paper (Other academic)
  • 23.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Forsman, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Studenters upplevelser av första året2012In: Universitetspedagogisk utveckling och kvalitet - i praktiken / [ed] Geir Gunnlaugsson, 2012, p. 9-20Conference paper (Other academic)
  • 24.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Haglund, Jesper
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Same goal, but different paths: Learning, explaining and understanding entropy2015In: / [ed] Stefan Pålsson, 2015Conference paper (Refereed)
    Abstract [en]

    Engineering students train to discuss conclusionsand results in different ways as part of their education. This is often done in connection to learning disciplinary knowledge where comparisons with and connections to previous courses play an important role. Students from different programs can have distinctly different repertoires of concepts and experiences when starting a course. This influences their learning on the course and how they communicate afterwards. We explore this issue in relation to engineering students’ explanations about entropy and how these change during a course in thermodynamics. A questionnaire study was done during the spring semester 2014 with students enrolling in a course on chemical thermodynamics. Students were asked to explain the concept of entropy and list scientific concepts they relate to entropy both before and after the course. A qualitative analysis was done for the 73 students who answered the questionnaire both before and after the course. Analysis showed that disorder was the most common aspect in student explanations, both before and after the course, but that many students used the concept ina more critical and reflective manner after the course. We also found that student explanations develop in richness by involving more aspects after the course. This development is dependent on the resources students bring with them when enrolling in the course. This is especially clear for students from the Master Programme in Chemical Engineering, who to a larger extent use microscopic elements, such as interaction between particles, in their explanations already before the course.

  • 25.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Johansson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Salminen Karlsson, Minna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Negotiating a Practice of Learning2015Conference paper (Refereed)
    Abstract [en]

    Research on study choice and participation in higher education, particularly in science and engineering, stresses the importance of students' on-going identity work as learners (Holmegard, Ulriksen & Madsen, 2014; Henriksen, Dillon & Ryder, 2015), especially on the scale of field of study. Our project explore how such identity work takes place on course level.

    An interview study concerning course achievement was undertaken with 21 students on a third-semester physics course. An interpretative discourse analysis (Gee, 2011) of the interviews yielded a model for students' negotiations of their practice in the course. Three types of practice were described: Ignoring to study, Studying to pass, and Studying to learn. The choice between these was influenced by the significance recognized for the course. This recognition, in turn, was generally discussed in relation to identity, largely connected to programme affiliation.

    This negotiation process becomes especially relevant when differently profiled programmes allow students to recognize and expect different ways of doing disciplines. However, in the study context they often study the same courses. We will present examples of the consequences this can have, based on quantitative data from the fields of physics and economics. Our results emphasize the importance of designing and teaching courses in a way that enable all students to recognize them as significant, to encourage both learning and participation.

    References

    Gee, J.P. (2011). An introduction to discourse analysis: theory and method. (3rd ed.). New York: Routledge.

    Henriksen, E.K., Dillon, J., & Ryder, J. (Eds.). (2015). Understanding student participation and choice in science and technology education. Springer.

    Holmegaard, H.T., Ulriksen, L.M., & Madsen, L.M. (2014). The process of choosing what to study: A longitudinal study of upper secondary students' identity work when choosing higher education. Scandinavian Journal of Educational Research, 58(1), 21-40.

  • 26.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Johansson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Salminen Karlsson, Minna
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Centre for Gender Research.
    Recognizing the significance of electromagnetism as identity work of engineering students2015Conference paper (Refereed)
    Abstract [en]

    Differences in student achievement, as measured by course grades, were explored on a third-semester Electromagnetism course through a mixed-methods approach. Interpretative discourse analysis of interviews showed how students describe their studying in relation to practice, significance and identity. Students that only saw a formal significance of the course, as an eligibility requirement, related to a practice of Studying to pass. A practice of Studying to pass was related to the recognition of vocational and disciplinary significance of the course. Program affiliation, associated with different views regarding vocations and the discipline of physics, were described as central for the on-going identity work of these students as learners. The results indicated that program affiliation played a central role for student achievement on the course. This was corroborated by a quantitative analysis showing that male and female students on most programs performed equally. This study was initiated to inform pedagogical development with the outspoken goal to

    help all female students, but the situation was not that simple. Our results emphasize the importance designing and teaching courses in a way that enable all students to recognize them as significant, to encourage both learning and participation.

  • 27.
    Antila, Liisa J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Ghamgosar, Pedram
    Maji, Somnath
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Tian, Haining
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Ott, Sascha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Dynamics and Photochemical H-2 Evolution of Dye-NiO Photocathodes with a Biomimetic FeFe-Catalyst2016In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 1, no 6, p. 1106-1111Article in journal (Refereed)
    Abstract [en]

    Mesoporous NiO films were cosensitized with a coumarin 343 dye and a proton reduction catalyst of the [Fe-2(CO)(6)(bdt)] (bdt = benzene-1,2-dithiolate) family. Femtosecond ultraviolet visible transient absorption experiments directly demonstrated subpicosecond hole injection into NiO from excited dyes followed by rapid (t(50%) similar to 6 ps) reduction of the catalyst on the surface with similar to 70% yield. The reduced catalyst was long-lived (2 mu s to 20 ms), which may allow protonation and a second reduction step of the catalyst to occur. A photo electrochemical device based on this photocathode produced H-2 with a Faradaic efficiency of similar to 50%. Fourier transform infrared spectroscopy and gas chromatography experiments demonstrated that the observed device deterioration with time was mainly due to catalyst degradation and desorption from the NiO surface. The insights gained from these mechanistic studies, regarding development of dye-catalyst cosensitized photocathodes, are discussed.

  • 28.
    Antila, Liisa J.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Santomauro, Fabio G.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Fernandes, Daniel L. A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Sa, Jacinto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hunting for the elusive shallow traps in TiO2 anatase2015In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 51, no 54, p. 10914-10916Article in journal (Refereed)
    Abstract [en]

    Understanding electron mobility on TiO2 is crucial because of its applications in photocatalysis and solar cells. This work shows that shallow traps believed to be involved in electron migration in TiO2 conduction band are formed upon band gap excitation, i.e., are not pre-existing states. The shallow traps in TiO2 results from large polarons and are not restricted to surface.

  • 29. Aquila, Andrew
    et al.
    Hunter, Mark S.
    Doak, R. Bruce
    Kirian, Richard A.
    Fromme, Petra
    White, Thomas A.
    Andreasson, Jakob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Arnlund, David
    Bajt, Saša
    Barends, Thomas R. M.
    Barthelmess, Miriam
    Bogan, Michael J.
    Bostedt, Christoph
    Bottin, Hervé
    Bozek, John D.
    Caleman, Carl
    Coppola, Nicola
    Davidsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    DePonte, Daniel P.
    Elser, Veit
    Epp, Sascha W.
    Erk, Benjamin
    Fleckenstein, Holger
    Foucar, Lutz
    Frank, Matthias
    Fromme, Raimund
    Graafsma, Heinz
    Grotjohann, Ingo
    Gumprecht, Lars
    Hajdu, Janos
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Hampton, Christina Y.
    Hartmann, Andreas
    Hartmann, Robert
    Hau-Riege, Stefan
    Hauser, Günter
    Hirsemann, Helmut
    Holl, Peter
    Holton, James M.
    Hömke, André
    Johansson, Linda
    Kimmel, Nils
    Kassemeyer, Stephan
    Krasniqi, Faton
    Kühnel, Kai-Uwe
    Liang, Mengning
    Lomb, Lukas
    Malmerberg, Erik
    Marchesini, Stefano
    Martin, Andrew V.
    Maia, Filipe R.N.C.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Messerschmidt, Marc
    Nass, Karol
    Reich, Christian
    Neutze, Richard
    Rolles, Daniel
    Rudek, Benedikt
    Rudenko, Artem
    Schlichting, Ilme
    Schmidt, Carlo
    Schmidt, Kevin E.
    Schulz, Joachim
    Seibert, M. Marvin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Soltau, Heike
    Shoeman, Robert L.
    Sierra, Raymond
    Starodub, Dmitri
    Stellato, Francesco
    Stern, Stephan
    Strüder, Lothar
    Timneanu, Nicusor
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Ullrich, Joachim
    Wang, Xiaoyu
    Williams, Garth J.
    Weidenspointner, Georg
    Weierstall, Uwe
    Wunderer, Cornelia
    Barty, Anton
    Spence, John C. H.
    Chapman, Henry N.
    Time-resolved protein nanocrystallography using an X-ray free-electron laser2012In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, no 3, p. 2706-2716Article in journal (Refereed)
    Abstract [en]

    We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photoactivated states of large membrane protein complexes in the form of nanocrystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 µs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time-resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems.

  • 30.
    Arkhypchuk, Anna I.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Mijangos, Edgar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Lomoth, Reiner
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Ott, Sascha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Redox Switching in Ethenyl- Bridged Bisphospholes2014In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 49, p. 16083-16087Article in journal (Refereed)
    Abstract [en]

    A 2e(-)/2H(+) redox platform has been implemented in the ethenyl-bridged bisphosphol-3-ol 1 to afford the first phospholes that feature chemically reversible oxidations. Oxidation of the title compounds to the corresponding bisphosphol-3-one 2 leads to a change in conjugation topology and a concomitant hypsochromic shift of the lowest-energy absorption maximum by 100nm. Electrochemical oxidation proceeds without any detectable intermediates, whereas the deprotonated form of 1 can be observed in an aprotic medium during the reduction of 2. This dianionic intermediate 3 is characterized by end absorptions that are bathochromically shifted by circa 200nm compared to those of 2.

  • 31. Arnlund, David
    et al.
    Johansson, Linda C
    Wickstrand, Cecilia
    Barty, Anton
    Williams, Garth J
    Malmerberg, Erik
    Davidsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Milathianaki, Despina
    DePonte, Daniel P
    Shoeman, Robert L
    Wang, Dingjie
    James, Daniel
    Katona, Gergely
    Westenhoff, Sebastian
    White, Thomas A
    Aquila, Andrew
    Bari, Sadia
    Berntsen, Peter
    Bogan, Mike
    van Driel, Tim Brandt
    Doak, R Bruce
    Kjær, Kasper Skov
    Frank, Matthias
    Fromme, Raimund
    Grotjohann, Ingo
    Henning, Robert
    Hunter, Mark S
    Kirian, Richard A
    Kosheleva, Irina
    Kupitz, Christopher
    Liang, Mengning
    Martin, Andrew V
    Nielsen, Martin Meedom
    Messerschmidt, Marc
    Seibert, M Marvin
    Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California, USA..
    Sjöhamn, Jennie
    Stellato, Francesco
    Weierstall, Uwe
    Zatsepin, Nadia A
    Spence, John C H
    Fromme, Petra
    Schlichting, Ilme
    Boutet, Sébastien
    Groenhof, Gerrit
    Chapman, Henry N
    Neutze, Richard
    Visualizing a protein quake with time-resolved X-ray scattering at a free-electron laser2014In: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 11, no 9, p. 923-926Article in journal (Refereed)
    Abstract [en]

    We describe a method to measure ultrafast protein structural changes using time-resolved wide-angle X-ray scattering at an X-ray free-electron laser. We demonstrated this approach using multiphoton excitation of the Blastochloris viridis photosynthetic reaction center, observing an ultrafast global conformational change that arises within picoseconds and precedes the propagation of heat through the protein. This provides direct structural evidence for a 'protein quake': the hypothesis that proteins rapidly dissipate energy through quake-like structural motions.

  • 32. Arteca, Gustavo A.
    et al.
    Aullo, Josep M.
    Tapia, Orlando
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Constructing quantum mechanical models starting from diabatic schemes: Quantum states for simulations bond break/formation-I. Feshbach-like quantum states and electronuclear wave functions2012In: Journal of Mathematical Chemistry, ISSN 0259-9791, E-ISSN 1572-8897, Vol. 50, no 4, p. 949-970Article in journal (Refereed)
    Abstract [en]

    A quantum description adapted to scrutinize chemical reaction mechanisms obtains by implementing an electronuclear separation via quantum numbers method; truly diabatic base states obtain that sustain quantum states expressed as linear superpositions. A proto-type bond breaking/formation case: H-2(+) double left right arrow H(1s) + H+ test possibilities via mathematical modeling. Asymptotic states (vertical bar H > circle times vertical bar H+>) and (vertical bar H+> circle times vertical bar H >) and basis states for quantized electromagnetic radiation complete the model; Feshbach-resonance-like quantum states obtain that play pivotal roles gating association/dissociation processes. A fixed grid of floating Gaussian orbitals permits actual computations compatible with this method. The information therefrom gleaned is used to construct model Hamiltonians easily adaptable to second quantization formalisms. Theoretical developments and non-routine computations results can directly be related to experiment.

  • 33.
    Arteca, Gustavo A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Laverdure, Laura
    Tapia-Olivares, Orlando
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Constructing quantum mechanical models from diabatic schemes: external field modulation of effective energy barriers for bond breaking/formation processes2014In: Journal of Mathematical Chemistry, ISSN 0259-9791, E-ISSN 1572-8897, Vol. 52, no 9, p. 2395-2410Article in journal (Refereed)
    Abstract [en]

    We have recently proposed an approach where chemical transformations can be described as quantum processes involving the modulation of entangled states by an applied external field (Arteca and Tapia in Phys Rev A 84:012115, 2011). In practical implementations, we gain insight into these processes by using simple quantum-mechanical models derived from diabatic schemes. In this context, reactant, product, and, eventually, intermediate species, are assigned to diabatic basis functions, and then entangled by an external field into a quantum state from which all observable properties of the chemical reaction should emerge. Here, we extend our previous model for bond breaking/formation in diatomic molecules (Arteca et al. in J Math Chem 50:949, 2012). We consider the entire manifold of semiclassical models defined by only two diabatic basis functions: a harmonic well for the "molecular" bound state, and an exponential potential energy function for the asymptotically separated fragments (the "product" channel). Using a two-parameter space to describe all models, we determine how the topology of the total energy function is affected by the shape of the applied field. We show that strong and weak local couplings with the external field modify substantially the occurrence of energy barriers, in contrast to using the uniform (i.e., space-invariant) coupling employed in previous works.

  • 34.
    Aster, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Univ Geneva, Dept Phys Chem, 30 Quai Ernest Ansermet, CH-1211 Geneva, Switzerland.
    Wang, Shihuai
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Mirmohades, Mohammad
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Esmieu, Charlène
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. CNRS, LCC, 205 Route Narbonne,BP 44099, F-31077 Toulouse 4, France.
    Berggren, Gustav
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lomoth, Reiner
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Metal vs. ligand protonation and the alleged proton-shuttling role of the azadithiolate ligand in catalytic H-2 formation with FeFe hydrogenase model complexes2019In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 10, no 21, p. 5582-5588Article in journal (Refereed)
    Abstract [en]

    Electron and proton transfer reactions of diiron complexes [Fe(2)adt(CO)(6)] (1) and [Fe(2)adt(CO)(4)(PMe3)(2)] (4), with the biomimetic azadithiolate (adt) bridging ligand, have been investigated by real-time IR- and UV-vis-spectroscopic observation to elucidate the role of the adt-N as a potential proton shuttle in catalytic H-2 formation. Protonation of the one-electron reduced complex, 1(-), occurs on the adt-N yielding 1H and the same species is obtained by one-electron reduction of 1H(+). The preference for ligand vs. metal protonation in the Fe-2(i,0) state is presumably kinetic but no evidence for tautomerization of 1H to the hydride 1Hy was observed. This shows that the adt ligand does not work as a proton relay in the formation of hydride intermediates in the reduced catalyst. A hydride intermediate 1HHy(+) is formed only by protonation of 1H with stronger acid. Adt protonation results in reduction of the catalyst at much less negative potential, but subsequent protonation of the metal centers is not slowed down, as would be expected according to the decrease in basicity. Thus, the adtH(+) complex retains a high turnover frequency at the lowered overpotential. Instead of proton shuttling, we propose that this gain in catalytic performance compared to the propyldithiolate analogue might be rationalized in terms of lower reorganization energy for hydride formation with bulk acid upon adt protonation.

  • 35.
    Aung, Su Htike
    et al.
    Uppsala Univ, Dept Chem, Angstrom Lab, POB 523, S-75120 Uppsala, Sweden.;Univ Mandalay, Dept Phys, Mat Sci Res Lab, Mahaaungmyay Township 100103, Mandalay, Myanmar..
    Hao, Yan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Oo, Than Zaw
    Univ Mandalay, Dept Phys, Mat Sci Res Lab, Mahaaungmyay Township 100103, Mandalay, Myanmar..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    2-(4-Butoxyphenyl)-N-hydroxyacetamide: An Efficient Preadsorber for Dye-Sensitized Solar Cells2017In: ACS OMEGA, ISSN 2470-1343, Vol. 2, no 5, p. 1820-1825Article in journal (Refereed)
    Abstract [en]

    The effect of chemical modification of mesoporous TiO2 electrodes by 2-(4-butoxyphenyl)-N-hydroxyacetamide (BPHA) before dye adsorption is investigated in dye-sensitized solar cells (DSCs). Two organic dyes, LEG4 and Dyenamo blue, were used in combination with the cobalt (II/III) tris(bipyridine) redox couple. The photovoltaic performance of the DSCs is clearly enhanced by BPHA. Preadsorption of mesoporous TiO2 electrodes with BPHA lowered the amount of adsorbed dye but improved the shortcircuit current densities and the power conversion efficiencies by 10-20%, while keeping the open-circuit potential essentially unaffected. Notably, BPHA improved the LEG4 performance, whereas it has been reported for this dye that chenodeoxycholic acid as a coadsorbent lowers solar cell efficiency. Faster dye regeneration was found to be one reason for improved performance, but improved electron injection efficiency may also contribute to the favorable effect of BPHA.

  • 36.
    Aung, Su Htike
    et al.
    Mandalay Univ, Mat Sci Res Lab, Dept Phys, Mandalay, Myanmar..
    Hao, Yan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Oo, Than Zaw
    Mandalay Univ, Mat Sci Res Lab, Dept Phys, Mandalay, Myanmar..
    Boschloo, Gerrit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Kinetic study of carminic acid and santalin natural dyes in dye-sensitized solar cells2016In: Journal of Photochemistry and Photobiology A: Chemistry, ISSN 1010-6030, E-ISSN 1873-2666, Vol. 325, p. 1-8Article in journal (Refereed)
    Abstract [en]

    The performance of natural dyes in dye-sensitized solar cells is usually worse than that of purpose-built organic dyes. Here, we set out to investigate the underlying origins. Two natural dyes, carminic acid and santalin, were selected as potential sensitizers for dye-sensitized solar cells. They were compared to a state-of-the-art organic sensitizer, LEG4, in devices using relatively thin (5 mu m), transparent mesoporous TiO2 electrodes and iodide/triiodide redox electrolyte in the low-volatile solvent 3-methoxypropionitrile. All dyes adsorbed well onto mesoporous TiO2 electrodes, giving it bright red colors. The power conversion efficiency of the natural dyes, about 0.5%, was poor compared to that of LEG4 under identical conditions (5.6%), due to both lower open circuit potentials and photocurrent densities. The origin of low efficiencies was investigated using a wide range of experimental techniques, such as (spectro)electrochemistry, ns-laser transient absorption spectroscopy and transient photocurrent and photovoltage measurements. The kinetics for regeneration of the oxidized natural dyes by iodide was found to about ten times slower than that of LEG4. This is probably due to the lower driving force for this reaction. Significant electron recombination to oxidized dye molecules and possibly poor electron injection efficiency caused the poor performance of the two natural dyes in dye-sensitized solar cells. In addition, for carminic acid electron injection into the conduction band of TiO2 appears to be poor. (C) 2016 Published by Elsevier B.V.

  • 37. Awais, Muhammad
    et al.
    Gibson, Elizabeth
    Vos, Johannes G.
    Dowling, Denis P.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Dini, Danilo
    Fabrication of Efficient NiO Photocathodes Prepared via RDS with Novel Routes of Substrate Processing for p-Type Dye-Sensitized Solar Cells2014In: CHEMELECTROCHEM, ISSN 2196-0216, Vol. 1, no 2, p. 384-391Article in journal (Refereed)
    Abstract [en]

    p-type dye sensitized solar cells (p-DSCs) derived from nickel oxide (NiO) photocathodes have been obtained via rapid discharge sintering (RDS) of parent metal oxide nanoparticles deposited onto differently treated substrates utilizing a plasma atmosphere with microwave radiation as heat source. This method produces NiO thin films (0.6 < l < 6 mu m) with mesoporous features and large surface areas as required for efficient dye-loading and high photocurrents. Erythrosine B (ERY) was used to sensitize the oxide in the visible spectrum. We have analyzed and compared the photoelectrochemical performances of the p-DSCs assembled with the various types of NiO samples prepared by RDS techniques with different treatments of the supporting substrate prior to, or during, spray deposition of the NiO nanoparticles. The best photovoltaic performances were obtained when the transparent conducting substrate (TCS) was heated during spraying. We believe that this is because the charge transfer through the NiO film and the charge collection at the TCS/NiO film interface were the most efficient with this sample. To our knowledge, the photovoltaic performances reported here are the best achieved with the commercial dye ERY as sensitizer.

  • 38.
    Ayub, Rabia
    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.
    Papadakis, Raffaello
    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.
    Jorner, Kjell
    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. uppsala university.
    Zietz, Burkhard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Ottosson, Henrik
    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. uppsala university.
    Cyclopropyl Group: An Excited-State Aromaticity Indicator?2017In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 55, p. 13684-13695Article in journal (Refereed)
    Abstract [en]

    The cyclopropyl (cPr) group, which is a well-known probe for detecting radical character at atoms to which it is connected, is tested as an indicator for aromaticity in the first * triplet and singlet excited states (T-1 and S-1). Baird's rule says that the -electron counts for aromaticity and antiaromaticity in the T-1 and S-1 states are opposite to Huckel's rule in the ground state (S-0). Our hypothesis is that the cPr group, as a result of Baird's rule, will remain closed when attached to an excited-state aromatic ring, enabling it to be used as an indicator to distinguish excited-state aromatic rings from excited-state antiaromatic and nonaromatic rings. Quantum chemical calculations and photoreactivity experiments support our hypothesis; calculated aromaticity indices reveal that openings of cPr substituents on [4n]annulenes ruin the excited-state aromaticity in energetically unfavorable processes. Yet, polycyclic compounds influenced by excited-state aromaticity (e.g., biphenylene), as well as 4n-electron heterocycles with two or more heteroatoms represent limitations.

  • 39. Bagheri, Narjes
    et al.
    Aghaei, Alireza
    Ghotbi, Mohammad Yeganeh
    Marzbanrad, Ehsan
    Vlachopoulos, Nick
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Haggman, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Wang, Michael
    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.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Skunik-Nuckowska, Magdalena
    Kulesza, Pawel. J.
    Combination of Asymmetric Supercapacitor Utilizing Activated Carbon and Nickel Oxide with Cobalt Polypyridyl-Based Dye-Sensitized Solar Cell2014In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 143, p. 390-397Article in journal (Refereed)
    Abstract [en]

    A dye-sensitized solar cell (DSC) based on the metal-free organic sensitizer and the cobalt (II, III) polypyridyl electrolyte was integrated here within an asymmetric supercapacitor utilizing cobalt-doped nickel oxide and activated carbon as positive and negative electrodes, respectively. A low cost nickel foil served as intermediate (auxiliary) bifunctional electrode separating two parts of the device and permitting the DSC electrolyte regeneration at one side and charge storage within cobalt-doped nickel oxide at the other. The main purpose of the research was to develop an integrated photocapacitor system capable of both energy generation and its further storage. Following irradiation at the 100 mW cm(-2) level, the solar cell generated an open-circuit voltage of 0.8 V and short-circuit current of 8 mA cm(-2) which corresponds to energy conversion efficiency of 4.9%. It was further shown that upon integration with asymmetric supercapacitor, the photogenerated energy was directly injected into porous charge storage electrodes thus resulting in specific capacitance of 32 F g(-1) and energy density of 2.3 Wh kg(-1). The coulumbic and total (energy conversion and charge storage) efficiency of photocapacitor were equal to 54% and 0.6%, respectively.

  • 40.
    Bagheri, Narjes
    et al.
    Mat & Energy Res Ctr, Div Ceram, POB 31787-316, Karaj, Iran..
    Aghaei, Alireza
    Mat & Energy Res Ctr, Div Ceram, POB 31787-316, Karaj, Iran..
    Vlachopoulos, Nick
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Skunik-Nuckowska, Magdalena
    Univ Warsaw, Fac Chem, Pasteura 1, PL-02093 Warsaw, Poland..
    Kulesza, Pawel J.
    Univ Warsaw, Fac Chem, Pasteura 1, PL-02093 Warsaw, Poland..
    Häggman, Leif
    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.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Univ Paris 07, Sorbonne Paris Cite, CNRS, UMR 7086,ITODYS, 15 Rue Jean Antoinede Baif, F-75205 Paris 13, France.;Sungkyankwan Univ, Sch Chem Engn, Suwon 440746, South Korea..
    Physicochemical identity and charge storage properties of battery-type nickel oxide material and its composites with activated carbon2016In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 194, p. 480-488Article in journal (Refereed)
    Abstract [en]

    The structural properties of annealed nickel oxide and its composites with activated carbon (synthesized via simple precipitation methods) have been addressed using X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption/desorption method and scanning electron microscopy. The charge storage properties of materials have also been investigated in three-and two-electrode configurations by means of cyclic voltammetry and galvanostatic charging/discharging in alkaline media. The results are consistent with the view that, depending on a method of preparation, the resulting nickel oxide films may exhibit redox characteristics different from that typically observed for nickel oxide-based materials. It is demonstrated that faradaic-type (redox) reactions, that are typical for battery-like materials, contribute predominantly to the high electrode capacity of 257C g(-1) (at 0.1 A g(-1)). By combining nickel oxide with a capacitive material such as activated carbon within the two-electrode symmetric cell, systems with increased charge-storage capabilities have been obtained. The fact, that the voltage window of nickel oxide-based cell has been broadened positively from 0.6 V to 1 V upon introduction of activated carbon, has also resulted in the increase of the cell's energy and power densities as well. 

  • 41.
    Bai, Xue
    et al.
    Xian Univ Architecture & Technol, Sch Environm & Municipal Engn, Xian 710055, Shaanxi, Peoples R China.
    Yang, Lei
    Xian Univ Architecture & Technol, Sch Environm & Municipal Engn, Xian 710055, Shaanxi, Peoples R China.
    Hagfeldt, Anders
    Ecole Polytech Fed Lausanne, Inst Chem Sci & Engn, Lab Photomol Sci, CH-1015 Lausanne, Switzerland.
    Johansson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Jin, Pengkang
    Xian Univ Architecture & Technol, Sch Environm & Municipal Engn, Xian 710055, Shaanxi, Peoples R China.
    D35-TiO2 nano-crystalline film as a high performance visible-light photocatalyst towards the degradation of bis-phenol A2019In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 355, p. 999-1010Article in journal (Refereed)
    Abstract [en]

    Dye-sensitized photocatalytic suspension system for wastewater treatment is still limited in practice due to particle aggregation, fast charge carrier recombination, poor stability and recycling issue. In this study, we combine TiO2 nano-crystalline film with D35 organic dye to fabricate a new visible-light photocatalyst D35-TiO2, which exhibits excellent visible light absorption. Its transient photocurrent is almost 10 times higher than pure TiO2 under visible light illumination (lambda > 420 nm). Besides the well characterizations of the D35-TiO2 film, e.g., SEM, EDS, TEM, XRD, UV-Vis DRS, XPS, PL and I-T, degradation of bis-phenol A (BPA) is performed as the model reaction to test its photocatalytic activity. Meanwhile, we employ external bias in the reaction system to further enhance the photogenerated charge carrier separation, and improve the photocatalytic efficiency. Under the better experimental conditions of initial BPA concentration (5 mg/L), initial pH (pH 7), external bias (0.25 V) and sensitizer concentration (0.1 mM), BPA is almost completely degraded in 300 min, and the four intermediates are gradually mineralized. The ecotoxicity of BPA also decreases significantly after the photo-degradation. During the reaction, center dot O-2(-) plays a dominant role, meanwhile center dot OH and h(D35)(+) also contribute to the BPA degradation. After five cycles, the D35-TiO2 film still maintain the normal photocatalytic activity. Due to the high stability and recyclability, the D35-TiO2 nano-crystalline film provides a sustainable way for degrading micropollutants in wastewater.

  • 42. Barty, Anton
    et al.
    Caleman, Carl
    Aquila, Andrew
    Timneanu, Nicusor
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Lomb, Lukas
    White, Thomas A.
    Andreasson, Jakob
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Arnlund, David
    Bajt, Sasa
    Barends, Thomas R. M.
    Barthelmess, Miriam
    Bogan, Michael J.
    Bostedt, Christoph
    Bozek, John D.
    Coffee, Ryan
    Coppola, Nicola
    Davidsson, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    DePonte, Daniel P.
    Doak, R. Bruce
    Ekeberg, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Elser, Veit
    Epp, Sascha W.
    Erk, Benjamin
    Fleckenstein, Holger
    Foucar, Lutz
    Fromme, Petra
    Graafsma, Heinz
    Gumprecht, Lars
    Hajdu, Janos
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Hampton, Christina Y.
    Hartmann, Robert
    Hartmann, Andreas
    Hauser, Guenter
    Hirsemann, Helmut
    Holl, Peter
    Hunter, Mark S.
    Johansson, Linda
    Kassemeyer, Stephan
    Kimmel, Nils
    Kirian, Richard A.
    Liang, Mengning
    Maia, Filipe R. N. C.
    Malmerberg, Erik
    Marchesini, Stefano
    Martin, Andrew V.
    Nass, Karol
    Neutze, Richard
    Reich, Christian
    Rolles, Daniel
    Rudek, Benedikt
    Rudenko, Artem
    Scott, Howard
    Schlichting, Ilme
    Schulz, Joachim
    Seibert, M. Marvin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Shoeman, Robert L.
    Sierra, Raymond G.
    Soltau, Heike
    Spence, John C. H.
    Stellato, Francesco
    Stern, Stephan
    Strueder, Lothar
    Ullrich, Joachim
    Wang, X.
    Weidenspointner, Georg
    Weierstall, Uwe
    Wunderer, Cornelia B.
    Chapman, Henry N.
    Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements2012In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 6, no 1, p. 35-40Article in journal (Refereed)
    Abstract [en]

    X-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis(1). For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information(1-4). Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage. Instead, the diffracted X-rays are gated by a rapid loss of crystalline periodicity, producing apparent pulse lengths significantly shorter than the duration of the incident pulse. The shortest apparent pulse lengths occur at the highest resolution, and our measurements indicate that current X-ray free-electron laser technology(5) should enable structural determination from submicrometre protein crystals with atomic resolution.

  • 43.
    Benesperi, Iacopo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Uppsala Univ, Dept Chem, Angstrom Lab, S-75120 Uppsala, Sweden.
    Michaels, Hannes
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Freitag, Marina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    The researcher's guide to solid-state dye-sensitized solar cells2018In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 6, no 44, p. 11903-11942Article, review/survey (Refereed)
    Abstract [en]

    In order to sustainably support its ever-increasing energy demand, the human society will have to harvest renewable energy wherever and whenever possible. When converting light to electricity, silicon solar cells are the technology of choice to harvest direct sunlight due to their high performance and continuously dropping price. For diffused light and indoor applications, however, silicon is not the material of choice. To power the next gizmo in your smart home, dye-sensitized solar cells (DSCs) are a viable alternative. Made from inexpensive, earth-abundant, and non-toxic materials, DSCs perform best at low light intensity. So far, issues such as leakage of the liquid electrolyte and its corrosive nature have limited the commercialization of this technology. To overcome these limitations, solid-state DSCs (ssDSCs) - in which the liquid electrolyte is replaced by a solid material - have been developed. For many years their efficiencies have been poor, preventing them from being widely employed. In the past six years, however, research efforts have led them to rival with their liquid counterparts. Here, we will review recent advancements in the field of ssDSCs. Every device component will be acknowledged, from metal oxides and new dyes to novel hole transporters, dopants, counter-electrodes and device architectures. After reviewing materials, long-term stability of devices will be addressed, finally giving an insight into the future that awaits this exciting technology.

  • 44.
    Bengtson, Charlotta
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Ahlkvist, Mikaela
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Ekeroth, William
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Nilsen-Moe, Astrid
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Proos Vedin, Nathalie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Rodiuchkina, Katerina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Ye, Sofie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lundberg, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Theoretical Chemistry.
    Working as Partners: Course Development by a Student–Teacher Team2017In: International Journal for the Scholarship of Teaching & Learning, ISSN 1931-4744, E-ISSN 1931-4744, Vol. 11, no 2, article id Article 6Article in journal (Refereed)
    Abstract [en]

    A first-year undergraduate course at Uppsala University has been redesigned in a process exploring differentlevels of student participation. In the first part of the project, the student voice was heard through interviewsfocusing on the role of the course in the degree program. In the second part, a student-teacher team wasformed to develop course curriculum and teaching material in partnership. Among the implemented changeswere new seminars focusing on conceptual understanding, redesign of all lectures to include active studentparticipation, and a change of the course literature. The redesigned course significantly increased studentsatisfaction compared to previous years. Important success factors were involvement of the studentorganization to promote the project, institutional support, early selection of concrete development tasks, andallowing team members to choose what they wanted to develop according to their own expertise.

  • 45. Berger, Gilles
    et al.
    Fusaro, Luca
    Luhmer, Michel
    Czapla-Masztafiak, Joanna
    Lipiec, Ewelina
    Szlachetko, Jakub
    Kayser, Yves
    Fernandes, Daniel L. A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Sa, Jacinto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Dufrasne, Francois
    Bombard, Sophie
    Insights into the structure-activity relationships of chiral 1,2-diaminophenylalkane platinum(II) anticancer derivatives2015In: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, Vol. 20, no 5, p. 841-853Article in journal (Refereed)
    Abstract [en]

    The structure-activity relationships of chiral 1,2-diaminophenylalkane platinum(II) anticancer derivatives are studied, including interactions with telomeric- and genomic-like DNA sequences, the pKa of their diaqua species, structural properties obtained from DFT calculations and resonant X-ray emission spectroscopy. The binding modes of the compounds to telomeric sequences were elucidated, showing no major differences with conventional cis-platinum(II) complexes like cisplatin, supporting that the cis-square planar geometry governs the binding of small Pt(II) complexes to G4 structures. Double-stranded DNA platination kinetics and acid-base constants of the diaqua species of the compounds were measured and compared, highlighting a strong steric dependence of the DNA-binding kinetics, but independent to stereoisomerism. Structural features of the compounds are discussed on the basis of dispersion-corrected DFT, showing that the most active series presents conformers for which the platinum atom is well devoid of steric hindrance. If reactivity indices derived from conceptual DFT do not show evidences for different reactivity between the compounds, RXES experiments provide new insight into the availability of platinum orbitals for binding to nucleophiles.

  • 46.
    Besharat, Z.
    et al.
    KTH Royal Inst Technol, Dept Chem, Div Surface & Corros Sci, S-10044 Stockholm, Sweden.;KTH Royal Inst Technol, Mat Phys, ICT, S-16440 Stockholm, Sweden..
    Alvarez-Asencio, R.
    KTH Royal Inst Technol, Dept Chem, Div Surface & Corros Sci, S-10044 Stockholm, Sweden.;IMDEA Nanociencia, Inst Adv Studies, Faraday 9,Campus Cantoblanco, Madrid 28049, Spain..
    Tian, Haining
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Yu, S.
    KTH Royal Inst Technol, Dept Chem Fiber & Polymer Technol, S-10044 Stockholm, Sweden..
    Johnson, C. M.
    KTH Royal Inst Technol, Dept Chem, Div Surface & Corros Sci, S-10044 Stockholm, Sweden..
    Gothelid, M.
    KTH Royal Inst Technol, Mat Phys, ICT, S-16440 Stockholm, Sweden..
    Rutland, M. W.
    KTH Royal Inst Technol, Dept Chem, Div Surface & Corros Sci, S-10044 Stockholm, Sweden..
    In-situ evaluation of dye adsorption on TiO2 using QCM2017In: EPJ Photovoltaics, ISSN 2105-0716, Vol. 8, article id 80401Article in journal (Refereed)
    Abstract [en]

    We measured the adsorption characteristics of two organic dyes; triphenylamine-cyanoacrylic acid (TPA-C) and phenoxazine (MP13), on TiO2, directly in a solution based on quartz crystal microbalance (QCM). Monitoring the adsorbed amount as a function of dye concentration and during rinsing allows determination of the equilibrium constant and distinction between chemisorbed and physisorbed dye. The measured equilibrium constants are 0.8 mM(-1) for TPA-C and 2.4 mM(-1) for MP13. X-ray photoelectron spectroscopy was used to compare dried chemisorbed layers of TPA-C prepared in solution with TPA-C layers prepared via vacuum sublimation; the two preparation methods render similar spectra except a small contribution of water residues (OH) on the solution prepared samples. Quantitative Nanomechanical Mapping Atomic Force Microscopy (QNM-AFM) shows that physisorbed TPA-C layers are easily removed by scanning the tip across the surface. Although not obvious in height images, adhesion images clearly demonstrate removal of the dye.

  • 47.
    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.

  • 48.
    Bhunia, Asamanjoy
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Natl Inst Technol Puducherry, Dept Chem, Karaikal 609609, India.
    Johnson, Ben A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Czapla-Masztafiak, Joanna
    Polish Acad Sci, Inst Nucl Phys, PL-31342 Krakow, Poland.
    Sá, Jacinto
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry. Polish Acad Sci, Inst Phys Chem, Ul Kasprzaka 44-52, PL-01224 Warsaw, Poland.
    Ott, Sascha
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Formal water oxidation turnover frequencies from MIL-101(Cr) anchored Ru(bda) depend on oxidant concentration2018In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, p. 7770-7773Article in journal (Refereed)
    Abstract [en]

    The molecular water oxidation catalyst [Ru(bda)(L)(2)] has been incorporated into pyridine-decorated MIL-101(Cr) metal-organic frameworks. The resulting MIL-101@Ru materials exhibit turnover frequencies (TOFs) up to ten times higher compared to the homogenous reference. An unusual dependence of the formal TOFs on oxidant concentration is observed that ultimately arises from differing amounts of catalysts in the MOF crystals being active.

  • 49.
    Bi, Dongqin
    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.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    High-Efficient Solid-State Perovskite Solar Cell Without Lithium Salt in the Hole Transport Material2014In: NANO, ISSN 1793-2920, Vol. 9, no 5, p. 1440001-Article in journal (Refereed)
    Abstract [en]

    CH3NH3PbX (X Br, I, Cl) perovskites have recently been used as light absorbers in hybrid organic-inorganic solid-state solar cells, with efficiencies above 15%. To date, it is essential to add Lithium bis(Trifluoromethanesulfonyl) Imide (LiTFSI) to the hole transport materials (HTM) to get a higher conductivity. However, the detrimental er effect of high LiTFSI concentration on the charge transport, DOS in the conduction band of the TiO2 substrate and device stability results in an overall compromise for a satisfactory device. Using a higher mobility hole conductor to avoid lithium salt is an interesting alternative. Herein, we successfully made an efficient perovskite solar cell by applying a hole conductor PTAA (Poly[ bis(4-phenyl) (2,4,6-trimethylphenyl)amine]) in the absence of LiTFSI. Under AM 1.5 illumination of 100mW/cm(2), an efficiency of 10.9% was achieved, which is comparable to the efficiency of 12.3% with the addition of 1.3mM LiTFSI. An unsealed device without Li+ shows interestingly a promising stability.

  • 50.
    Bi, Dongqin
    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.
    Schwarzmueller, Stefan
    Yang, Lei
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Johansson, Erik M. J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Hagfeldt, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Efficient and stable CH3NH3PbI3-sensitized ZnO nanorod array solid-state solar cells2013In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 5, no 23, p. 11686-11691Article in journal (Refereed)
    Abstract [en]

    We report for the first time the use of a perovskite (CH3NH3PbI3) absorber in combination with ZnO nanorod arrays (NRAs) for solar cell applications. The perovskite material has a higher absorption coefficient than molecular dye sensitizers, gives better solar cell stability, and is therefore more suited as a sensitizer for ZnO NRAs. A solar cell efficiency of 5.0% was achieved under 1000 W m(-2) AM 1.5 G illumination for a solar cell with the structure: ZnO NRA/CH3NH3PbI3/spiro-MeOTAD/Ag. Moreover, the solar cell shows a good long-term stability. Using transient photocurrent and photovoltage measurements it was found that the electron transport time and lifetime vary with the ZnO nanorod length, a trend which is similar to that in dye-sensitized solar cells, DSCs, suggesting a similar charge transfer process in ZnO NRA/CH3NH3PbI3 solar cells as in conventional DSCs. Compared to CH3NH3PbI3/TiO2 solar cells, ZnO shows a lower performance due to more recombination losses.

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