| 1. |
- 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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| 2. |
- Lanzilotto, Valeria, et al.
(författare)
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The Challenge of Thermal Deposition of Coordination Compounds : Insight into the Case of an Fe-4 Single Molecule Magnet
- 2016
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 28:21, s. 7693-7702
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Tidskriftsartikel (refereegranskat)abstract
- Realization of well-controlled hybrid interfaces between solid surfaces and functional complex molecules can be hampered by the presence of contaminants originated by the fragmentation of fragile architectures based on the coordinative bond. Here, we present a morphological and spectroscopic analysis of submonolayer films obtained by sublimation of the [Fe-4(L)(2)(dpm)(6)] (Fe-4) single molecule magnet on different substrates. Though intact tetranuclear molecules can be transferred to surfaces, smaller molecular species are often codeposited. By comparison of substrates characterized by different reactivities, such as Au(111), Cu(100), and Cu2N, and employing a protocol of indirect exposure of the substrate, we infer that the observed fragments do not originate from the reaction of Fe-4 molecules with the surface but rather are produced during Fe-4 sublimation, which releases Fe(dpm)(3) as a very volatile compound. Fe(dpm)(3) undergoes substrate-dependent on-surface decomposition to final products that have been identified by combined STM, UPS, XPS, and DFT studies.
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| 3. |
- Ninova, Silviya, et al.
(författare)
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Suitability of Cu-substituted beta-Mn2V2O7 and Mn-substituted beta-Cu2V2O7 for photocatalytic water-splitting
- 2020
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 1089-7690 .- 0021-9606. ; 153:8
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Tidskriftsartikel (refereegranskat)abstract
- The pyrovanadates beta -Mn2V2O7 and beta -Cu2V2O7 were previously investigated as photoanode materials for water splitting. Neither of them, however, was found to be sufficiently active. In this work, we predict the properties of these two structurally similar pyrovanadates upon Cu/Mn substitution in their corresponding lattices via density functional theory calculations to explore the suitability of their band structure for water splitting and to assess their ease of synthesis. We predict that a concentration of up to 20% Cu and Mn into beta -Mn2V2O7 and beta -Cu2V2O7, respectively, leads to a narrowing of the bandgap, which, in the former case, is experimentally confirmed by UV-vis spectroscopy. Calculations in the intermediate composition range, however, yield nearly constant bandgaps. Moreover, we predict the materials with higher substitution levels to be increasingly difficult to synthesize, implying that low substitution levels are most relevant in terms of bandgaps and ease of synthesis.
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