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Article

Visible-Light-Response and Photocatalytic Activities of TiO₂ and SrTiO₃ Photocatalysts Codoped with Antimony and Chromium

Hideki Kato and Akihiko Kudo*

Department of Applied Chemistry, Faculty of Science, Science University of Tokyo, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan

J. Phys. Chem. B, 2002, 106 (19), pp 5029–5034

DOI: 10.1021/jp0255482

Publication Date (Web): April 23, 2002

To whom correspondence should be addressed. FAX: +81-33235-2214. E-mail: a-kudo@ch.kagu.sut.ac.jp.

Abstract

TiO₂ and SrTiO₃ codoped with antimony and chromium showed intense absorption bands in the visible light region and possessed 2.2 and 2.4 eV of energy gaps, respectively. TiO₂ codoped with antimony and chromium evolved O₂ from an aqueous silver nitrate solution under visible light irradiation, while SrTiO₃ codoped with antimony and chromium evolved H₂ from an aqueous methanol solution. The activity of TiO₂ photocatalyst codoped with antimony and chromium was remarkably higher than that of TiO₂ doped with only chromium. It was due to that the charge balance was kept by codoping of Sb⁵⁺ and Cr³⁺ ions, resulting in the suppression of formation of Cr⁶⁺ ions and oxygen defects in the lattice which should work as effectively nonradiative recombination centers between photogenerated electrons and holes.