Photocatalytic reactions sensitized by composite particles have been examined, which are composed of titanium dioxide and acceptor-doped perovskite involving alkali-earth elements. Although the photocatalytic activity of perovskite-type oxide Sr(Zr 0.90 Y 0.10 )O 3-δ being p-type conductor is weak, it absorbs light with wavelength of λ<800 nm. Titanium dioxide (TiO 2 ) being n-type conductor exhibits a fairly high photocatalytic activity; however, it does not absorb visible light. Under the irradiation of Xe discharge light, the composite particles involving the pn-junction exerted several times higher photocatalytic activity in photodegradation of methylene blue than a sole TiO 2 . Similar results were obtained for the composite powders of Sr(Zr 0.95 Y 0.05 )O 3-δ , Ca(Zr 0.95 Y 0.10 )O 3-δ and Ca(Zr 0.95 Ga 0.05 )O 3-δ with TiO 2 , respectively. Under the irradiation of visible light with wavelength of λ > 420 nm, it was found that the photodegradation of methylene blue and HCOOH aqueous solutions proceeded. These results may be explained by a model for the flow of the photogenerated electrons and holes through the pn-junctions in the composite particles.
|ジャーナル||Journal of Photochemistry and Photobiology A: Chemistry|
|出版ステータス||Published - 2003 3 20|
ASJC Scopus subject areas
- 化学 (全般)