Photo-oxidation reaction of water on an n-TiO2 electrode. Improvement in efficiency through formation of surface micropores by photo-etching in H2SO4

Autor:	Hideyuki Akanuma, Yoshifumi Magari, Jun-ichi Shimizu, Yoshihiro Nakato
Rok vydání:	1995
Předmět:	Photocurrent Photoluminescence Hydrogen General Chemical Engineering Inorganic chemistry Photoelectrochemistry chemistry.chemical_element Electrolyte Electrochemistry Photochemistry Analytical Chemistry chemistry Electrode Extrinsic semiconductor
Zdroj:	Journal of Electroanalytical Chemistry. 396:35-39
ISSN:	1572-6657
DOI:	10.1016/0022-0728(95)04007-b
Popis:	The photocurrent-potential curves and the photoluminescence (PL) peak at 840 nm for n-TiO 2 electrodes, in which the n-type semiconductivity is obtained by hydrogen reduction at 550–700°C are investigated in various electrolyte solutions. It is found that a freshly prepared n-TiO 2 electrode shows a weak photocurrent and no PL, but both the photocurrent and the PL intensity increase substantially with time when the electrode is illuminated during cyclic potential scans in 0.05 M H 2 SO 4 . This is accompanied by the formation of a large number of micropores at the electrode surface. No such activation is observed in 0.1 M HClO 4 and 0.5 M Na 2 SO 4 , but an n-TiO 2 electrode activated by illumination in H 2 SO 4 shows an efficient photocurrent and strong PL in these solutions. It is concluded that the increases in the photocurrent and the PL intensity are caused by the production of an active n-TiO 2 surface for the oxygen photoevolution reaction through the formation of surface micropores due to photoetching in H 2 SO 4 .
Databáze:	OpenAIRE
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