摘要 |
<p>"CATALYSTS FOR PHOTO-ASSISTED OXIDATION-REDUCTION REACTIONS" This invention relates to catalysts for photo-assisted (i.e. promoted by light) oxidation-reduction (redox) reactions. These catalysts consist of colloidal particles of a semiconductor, containing on their surface a reduction catalyst and an oxidation catalyst. In a first class of catalysts, the semiconductor has a difference of energy between the valence band and the conduction band such as to permit the hole-electron separation by absorption of visible light; this semiconductor is selected, in the case of the photodecomposition of water, from TiO2 doped with Mn, Cr or Cr and Nb; CdS doped with In or Ga; SrTiO3 doped with Cr or Mn; gallium phosphide and cadmium sulphoselenide; in the case of other photodecomposition reactions, the semiconductor is selected from the above-mentioned compounds and CdS. In a second class of catalysts, the semiconductor has a difference of energy between the valence band and the conduction band such as not to permit the hole-electron separation by absorption of visible light; this semiconductor is selected, in the case of the photodecomposition of water, from SrTiO3 and Nb2O5; in the case of other photodecomposition reactions, the semiconductor is selected from the above-mentioned compounds and TiO2 doped with Nb.</p> |