TY - JOUR
T1 - "Roll-on" nano-CIGSe film electrodes in photo-hydrogenation
AU - Abid, M. Saleem
AU - Ahmed, S.
AU - Ahmed, E.
AU - Hussain, S.
AU - Kiermaier, J.
AU - Matysik, F.-M.
AU - Kociok-Kohn, Gabriele
AU - Mitchels, J.M.
AU - Marken, F.
PY - 2013/2/15
Y1 - 2013/2/15
N2 - Commercial nano-CIGSe powder (nominal CuIn0.7Ga0.3Se2, average particle size <100 nm) is applied to tin-doped indium oxide (ITO) electrodes in a simple "roll-on" process from n-hexanol to give thin photo-electrochemically active films. Films "as deposited" and "annealed" in selenium atmosphere at 350 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) 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 μm 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.
AB - Commercial nano-CIGSe powder (nominal CuIn0.7Ga0.3Se2, average particle size <100 nm) is applied to tin-doped indium oxide (ITO) electrodes in a simple "roll-on" process from n-hexanol to give thin photo-electrochemically active films. Films "as deposited" and "annealed" in selenium atmosphere at 350 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) 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 μm 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.
UR - http://www.scopus.com/inward/record.url?scp=84891787930&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1016/j.jphotochem.2013.11.012
U2 - 10.1016/j.jphotochem.2013.11.012
DO - 10.1016/j.jphotochem.2013.11.012
M3 - Article
AN - SCOPUS:84891787930
SN - 1010-6030
VL - 276
SP - 65
EP - 70
JO - Journal of Photochemistry and Photobiology A Chemistry
JF - Journal of Photochemistry and Photobiology A Chemistry
ER -