| 1. |
- Abdala, Paula M, et al.
(författare)
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Scientific opportunities for heterogeneous catalysis research at the SuperXAS and SNBL beam lines.
- 2012
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Ingår i: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 66:9, s. 699-705
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Tidskriftsartikel (refereegranskat)abstract
- In this short review, we describe the complementary experimental capabilities for catalysis research at two beam lines available to the Swiss community, SuperXAS at SLS (Swiss Light Source, Villigen) and SNBL (Swiss Norwegian Beam lines) at ESRF (European Synchrotron Radiation Facility, Grenoble). Over the years, these two facilities have been developed to provide powerful techniques for structural studies under in situ and operando conditions. These techniques, X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and X-ray emission spectroscopy (XES) in combination with Raman or infrared spectroscopy provide new avenues for structure-performance studies of catalysts. Several exemplary studies are used to demonstrate the capability of these facilities.
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| 2. |
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| 3. |
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| 4. |
- Bauer, Georg, et al.
(författare)
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Biologically relevant small radicals
- 2008
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Ingår i: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 62:9, s. 704-712
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Tidskriftsartikel (refereegranskat)abstract
- Biologically relevant small radicals are at the focus of the working group 4 (WG4) of the COST Action CM0603 (Free Radicals in Chemical Biology, CHEMBIORADICAL). This article surveys the areas of research being undertaken by the partners in WG4. The character of the radicals is described together with experimental techniques utilized to follow their structure and reactivity. Specifically, C-, S-, N- and O-centered radicals of small size, and their interaction with different biomolecules are described. Processes at the molecular level exemplifying important biological signaling and damaging pathways are introduced.
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| 5. |
- Bouri, Maria, et al.
(författare)
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Surface Chemistry of Perovskite Oxynitride Photocatalysts: A Computational Perspective
- 2021
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Ingår i: Chimia. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 75:3, s. 202-207
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite oxynitrides are an established class of photocatalyst materials for water splitting. Previous computational studies have primarily focused on their bulk properties and have drawn relevant conclusions on their light absorption and charge transport properties. The actual catalytic conversions, however, occur on their surfaces and a detailed knowledge of the atomic-scale structure and processes on oxynitride surfaces is indispensable to further improve these materials. In this contribution, we summarize recent progress made in the understanding of perovskite oxynitride surfaces, highlight key processes that set these materials apart from their pure oxide counterparts and discuss challenges and possible future directions for research on oxynitrides.
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| 6. |
- Cuartero, Maria, et al.
(författare)
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Thin Layer Samples Controlled by Dynamic Electrochemistry
- 2015
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Ingår i: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 69:4, s. 203-206
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Tidskriftsartikel (refereegranskat)abstract
- We summarize here recent advancements on thin layer samples controlled by dynamic electrochemistry techniques for determining different ions that include potassium, calcium, protamine, nitrate, nitrite and halides in diverse environmental and clinical samples. Generally, a thin layer liquid (less than 100 μm in thickness) is confined between a working electrode and an ion-selective membrane. Once an external electrical perturbation (i.e. constant potential) is applied to the system, an exhaustive ion transfer process is imposed in the entire thin layer solution. As a result, the observed charge (integration of the current decay) is proportional to the depleted ion concentration. Other electrochemical protocols such as linear sweep voltammetry were also explored aiming at the discrimination of several ions presented in the thin layer. One of the most attractive examples involves the detection of a mixture of three halides (iodide, bromide and chloride), which can be well resolved at moderated scan rates (10 mV.s–1). Paper-based coulometric sensing on thin layers defined by cellulose papers are being developed in view of translating these new concepts into a reliable and low cost sensing platform.
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| 8. |
- Karlsson, Martin, et al.
(författare)
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Dye-sensitized Solar Cells Employing a SnO2-TiO2 Core-shell Structure Made by Atomic Layer Deposition
- 2013
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Ingår i: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 67:3, s. 142-148
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the synthesis and characterization of core-shell structures, based on SnO2 and TiO2, for use in dye-sensitized solar cells (DSc). Atomic layer deposition is employed to control and vary the thickness of the TiO2 shell. Increasing the TiO2 shell thickness to 2 nm improved the device performance of liquid electrolyte-based DSC from 0.7% to 3.5%. The increase in efficiency originates from a higher open-circuit potential and a higher short-circuit current, as well as from an improvement in the electron. lifetime. SnO2-TiO2 core-shell DSC devices retain their photovoltage in darkness for longer than 500 seconds, demonstrating that the electrons are contained in the core material. Finally core-shell structures were used for solid-state DSC applications using the hole transporting material 2,2',7,7',-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Similar improvements in device performance were obtained for solid-state DSC devices.
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| 9. |
- Luque, Francisco J., et al.
(författare)
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Enantiosensitive Bonding of Chiral Molecules on a Magnetic Substrate Investigated by Means of Electron Spectroscopies
- 2018
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Ingår i: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 72:6, s. 418-423
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of purely organic chiral molecules on ferromagnetic Co thin films is studied under ultra high vacuum conditions by means of synchrotron radiation-based electron spectroscopies, namely X-ray absorption and ultraviolet photoemission. X-ray absorption reveals that enantiomers with opposite handedness (R,R) - and (S,S)- of two different molecules adsorb with different strength on the Co surfaces and their valence band photoemission spectra also display distinctive features. In view of the recent reports describing the chiral-induced spin selectivity (CISS) effect these results lead us to consider the possibility that some enantiosensitivity may appear when bonding chiral molecules to a substrate with an initial asymmetry in the population of the different spin orientations.
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