| abstract |
A titanium oxide-based photocatalyst which can exhibit excellent photocatalytic properties in response to visible light while maintaining its inherent activity in response to ultraviolet light and which is suitable for mass production contains bismuth as a first additional metal component and at least one metal element selected from silicon, zirconium, aluminum, and hafnium as a second additional metal component in titanium oxide. The Bi/Ti atomic ratio is preferably at least 0.0001 and at most 1.0, the atomic ratio of the second additional metal to Ti is preferably at least 0.0001 and at most 0.8, and a portion of bismuth is preferably present in the form of lower valence (Bi 2+ or Bi 0 ). The presence of lower valence bismuth can be ascertained by XPS analysis. |