Thermal sulfidation of alpha-Fe2O3 hematite to FeS2 pyrite thin electrodes: Correlation between surface morphology and photoelectrochemical functionality

0492863 - FZÚ 2019 RIV NL eng J - Journal Article
Kmentová, H. - Kment, Š. - Hubička, Zdeněk - Remeš, Zdeněk - Olejníček, Jiří - Čada, Martin - Krýsa, J. - Zbořil, R.
Thermal sulfidation of alpha-Fe2O3 hematite to FeS2 pyrite thin electrodes: Correlation between surface morphology and photoelectrochemical functionality.
Catalysis Today. Roč. 313, Sep (2018), s. 224-230. ISSN 0920-5861. E-ISSN 1873-4308
R&D Projects: GA ČR(CZ) GA15-00863S; GA ČR GA17-20008S
Institutional support: RVO:68378271
Keywords : hematite * HiPIMS * PEC activity * photoelectrochemical PV cell * pyrite * sol-gel * thermal sulfidation
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 4.888, year: 2018

We studied for the first time the correlation between photoelectrochemical (PEC) functionality of hematite films and after their sulfidation into pyrite. The highest PEC activity of hematite films of 560 uA cm−2 at 700 mV vs. Ag/AgCl was achieved with the HiPIMS photoelectrodes. The photoefficiency dropped dramatically to 4 uA cm−2 at 600 mV vs. Ag/AgCl after the sulfidation. A significant increase of grains‘ size, residual unreacted hematite, surface defects were the main reasons for the poor photoactivity. The sol-gel produced hematite yielded photocurrent of 30 uA cm−2 and a slight increase to 40 μA cm−2 (recorded at 500 mV vs. Ag/AgCl) of the corresponding pyrite version. Both these electrodes showed also similar morphological characteristics. The structural, electronic and optical properties of the deposited films were determined using various methods e.g. Raman spectroscopy, SEM, and PDS.
Permanent Link: http://hdl.handle.net/11104/0286324