Fe2O3 photoanodes: Photocorrosion protection by thin SnO2 and TiO2 films

0542520 - ÚFCH JH 2022 RIV CH eng J - Journal Article
Imrich, T. - Krýsová, Hana - Neumann-Spallart, M. - Krýsa, J.
Fe2O3 photoanodes: Photocorrosion protection by thin SnO2 and TiO2 films.
Journal of Electroanalytical Chemistry. Roč. 892, JUL 2021 (2021), č. článku 115282. ISSN 1572-6657. E-ISSN 1873-2569
R&D Projects: GA ČR(CZ) GA20-11635S; GA MŠMT(CZ) LM2018124
Institutional support: RVO:61388955
Keywords : Aerosol pyrolysis * ald * Hematite * Photocorrosion * SnO 2 * TiO 2
OECD category: Physical chemistry
Impact factor: 4.598, year: 2021
Method of publishing: Limited access

The possibility of protection of Fe2O3 (hematite) against photocorrosion in aqueous electrolytes by thin layers of TiO2 and SnO2 deposited by ALD (atomic layer deposition), was investigated. Sn-doped hematite layers, as obtained in this study by aerosol pyrolysis had significant roughness and porosity. ALD is very successful in applying conformal films to such structures. The nominal coverage by ALD films was varied between 0.5 and 7.5 nm. The presence of the TiO2 and SnO2 films was evidenced by XPS. Photocurrents were strongly diminished as the capping layer thickness was increased. The Faradaic efficiency, f, of photocorrosion in acidic media (0.01 M H2SO4) was decreased from 0.026 to 0.014 and to 0.010 by capping with either a 2 nm thick overlayer of TiO2 or of SnO2, respectively. The latter had also a positive influence on the long term photocurrent stability.
Permanent Link: http://hdl.handle.net/11104/0319916