Interface analysis and development of BiVO4 and CuFeO2 heterostructures for photochemical water splitting
Solar photo(electro)chemical (PEC) water splitting is regarded as a promising ways of renewable hydrogen production. Especially, type 2 PEC systems, in which the necessary energy needed to split water can be supplied by two complimentary photoabsorbers, have the potential to economically compete wit...
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| Format: | Others |
| Language: | en |
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2019
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| Online Access: | http://tuprints.ulb.tu-darmstadt.de/8700/1/Complete_thesis%20-%20German.pdf Hermans, Yannick <http://tuprints.ulb.tu-darmstadt.de/view/person/Hermans=3AYannick=3A=3A.html> : Interface analysis and development of BiVO4 and CuFeO2 heterostructures for photochemical water splitting. Technische Universität, Darmstadt [Ph.D. Thesis], (2019) |
| Summary: | Solar photo(electro)chemical (PEC) water splitting is regarded as a promising ways of renewable hydrogen production. Especially, type 2 PEC systems, in which the necessary energy needed to split water can be supplied by two complimentary photoabsorbers, have the potential to economically compete with steam methane reforming, the conventional hydrogen production method. In this work, BiVO4 and CuFeO2 were chosen to perform the water oxidation and water reduction reaction, respectively. However, according to literature additional contact materials are required to achieve a reasonable water splitting performance.
The exact benefits of these contact materials have not yet been completely elucidated. Therefore, we opted in this work to investigate the junction properties of certain BiVO4 and CuFeO2 based heterostructures through so called interface experiments, whereby a certain contact material was stepwise sputtered onto a BiVO4 or CuFeO2 substrate, performing photoelectron spectroscopy measurements in between each deposition step. In this way we could interpret the band
alignment between the substrate and the contact material, as well as determine the Fermi level tunability for the studied photoabsorbers.
In parallel, new anisotropic CuFeO2 and BiVO4 based heterostructured powders were created through photodeposition. In particular, silver, platinum, cobalt(oxy)(hydr)oxide and nickel(oxy)(hydr)oxide were successfully deposited onto anisotropically shaped BiVO4 and CuFeO2 powders. These powders were tested as well for their performance in photochemical water splitting. |
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