Role of Iron Ion Electron Mediator on Photocatalytic Overall Water Splitting under Visible Light Irradiation Using Z-Scheme Systems

• Hideki Kato

  Department of Applied Chemistry, Faculty of Science, Tokyo University of Science

• Yasuyoshi Sasaki

  Department of Applied Chemistry, Faculty of Science, Tokyo University of Science

• Akihide Iwase

  Department of Applied Chemistry, Faculty of Science, Tokyo University of Science

• Akihiko Kudo

  Department of Applied Chemistry, Faculty of Science, Tokyo University of Science

抄録

A combination system consisting of a H2 production photocatalyst, Pt/SrTiO3:Rh, and an O2 production photocatalyst, BiVO4 or WO3, decomposed water into H2 and O2 under visible light irradiation in the presence of an Fe3+/Fe2+ redox couple as an electron mediator. O2 evolution on the BiVO4 photocatalyst was inhibited by Fe2+ ions, because of the oxidation of Fe2+ instead of water. In contrast, H2 evolution on the Pt/SrTiO3:Rh photocatalyst was enhanced when Fe3+ ions co-existed. It is due to the back-reactions between H2 and O2 to form water, and the reduction of Fe3+ by H2, which easily proceeded on the bare Pt cocatalyst surface, being efficiently suppressed by adsorption of [Fe(SO4)(H2O)5]+ and/or [Fe(OH)(H2O)5]2+ on the Pt surface. Overall water splitting was achieved with the suppression of the back-reactions even using a Pt cocatalyst. Thus, it clears that iron ions contributed to the present Z-scheme systems not only as an electron mediator but also as an inhibitor of the back-reactions.

収録刊行物

• Bulletin of the Chemical Society of Japan

  Bulletin of the Chemical Society of Japan 80 (12), 2457-2464, 2007-12

  Oxford University Press (OUP)

キーワード

• General Chemistry

詳細情報

• CRID: 1360846644035345664
• NII論文ID: 130004152239
• DOI: 10.1246/bcsj.80.2457
• ISSN: 13480634
• ISSN: 00092673
• Web Site: https://academic.oup.com/bcsj/article-pdf/80/12/2457/56268929/bcsj.80.2457.pdf
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