鈥淩oll-on鈥?nano-CIGSe film electrodes in photo-hydrogenation

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• 作者：Muhammad Saleem Abid ; Safeer Ahmed ; Ejaz Ahmed ; Sabir Hussain ; Josef Kiermaier ; Frank-Michael Matysik ; Gabriele Kociok-K枚hn ; John M. Mitchels ; Frank Marken
• 关键词：CIGS ; Photoelectrochemistry ; Photo-hydrogenation ; Olefin ; Solar fuels
• 刊名：Journal of Photochemistry and Photobiology A: Chemistry
• 出版年：15 February, 2013
• 年：2013
• 卷：276
• 期：Complete
• 页码：65-70
• 全文大小：1682 K

文摘

Commercial nano-CIGSe powder (nominal CuIn_0.7Ga_0.3Se₂, average particle size < 100 nm) is applied to tin-doped indium oxide (ITO) electrodes in a simple 鈥渞oll-on鈥?process from n-hexanol to give thin photo-electrochemically active films. Films 鈥渁s deposited鈥?and 鈥渁nnealed鈥?in selenium atmosphere at 350 掳C are compared with the latter performing substantially better. Perhaps surprisingly, photo-transient voltammetry suggests only insignificant effects when changing aqueous electrolyte from Eu(NO₃)₃ to KNO₃ or when changing electrolyte concentration, most likely due to a dominating electron-quenching process caused by dissolved dioxygen. However, when under inert argon atmosphere, generator-collector photo-transient voltammetry with a 50 渭m Pt collector microelectrode placed close to the CIGSe film surface proves photo-induced H₂ formation in 0.1 M KNO₃ or in 0.1 M HNO₃ (and it confirms electron-quenching by O₂ in the presence of air). In aqueous 0.1 M HNO₃ effective electron-quenching (photo-hydrogenation) with fumaric acid is observed with current yields of ca. 60% for fumarate to succinate conversion. Detrimental loss of photoelectrochemical activity (probably via photo-corrosion) with time occurs.