Electrochemical approach to evaluate the mechanism of photocatalytic water splitting on oxide photocatalysts

Yasumichi Matsumoto, Ugur Unal, Noriyuki Tanaka, Akihiko Kudo, Hideki Kato

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)

Abstract

Model of an oxide photocatalyst electrode. Photoelectrochemical measurements of TiO 2, NaTaO 3, and Cr or Sb doped TiO 2 and SrTiO 3 photocatalysts were carried out in H 2 and O 2 saturated electrolytes in order to evaluate the reverse reactions during water photolysis. The poor activity of TiO 2 as a result of reverse photoreactions of O 2 reduction and H 2 oxidation was revealed with the respective high cathodic and anodic photocurrents. The rise in the photocurrents at NaTaO 3 after La doping was in harmony with the doping-induced increase in the photocatalytic activity. NiO loading suppresses the O 2 photoreverse reactions, which declines photocatalytic activity, and/or promotes the photo-oxidation of water, because the O 2 photo-reduction current was scarcely observed near the flatband potential. Photocurrents of O 2 reduction and H 2 oxidation were observed under visible light for the Cr and Sb doped SrTiO 3 and TiO 2, respectively. These phenomena are in harmony with the previous reports on the photocatalysts examined with sacrificial reagents.

Original languageEnglish
Pages (from-to)4205-4212
Number of pages8
JournalJournal of Solid State Chemistry
Volume177
Issue number11
DOIs
Publication statusPublished - 2004 Nov 1
Externally publishedYes

Keywords

  • Doping
  • Oxide films
  • Oxide photocatalyst
  • Photochemistry
  • Reverse reactions
  • Semiconductor/solution interface
  • TiO
  • Water photolysis
  • Water splitting

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

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