Chemistry: electrical and wave energy – Processes and products – Processes of treating materials by wave energy
Patent
1982-07-15
1986-11-18
Metz, Andrew H.
Chemistry: electrical and wave energy
Processes and products
Processes of treating materials by wave energy
20415749, 2041575, 20415752, 204903, 502208, 502210, 502216, 501134, 501136, B01J 1912, B01J 2714, B01J 27188, B01J 2702
Patent
active
046234373
ABSTRACT:
New catalysts for photo-assisted (i.e. promoted by light) oxidation-reduction (redox) reactions are disclosed. 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 valence band and conduction band such as to allow the hole-electron separation by absorption of visible light. This semiconductor is selected, in the case of the photo-decomposition of water, from the group consisting of TiO.sub.2 doped with Mn, Cr, or Cr and Nb; CdS doped with In or Ga; SrTiO.sub.3 doped with Cr or Mn; gallium phosphide; and cadmium sulphoselenide. In the case of the other photo-decomposition reactions, the semiconductor is selected from the group consisting of the above-mentioned compounds and CdS.
In a second class of catalysts, the semiconductor has a difference of energy between valence band and 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 photo-decomposition of water, from the group consisting of SrTiO.sub.3 and Nb.sub.2 O.sub.5. In the case of the other photo-decompositon reactions, the semiconductor is selected from the group consisting of the above-mentioned compounds and TiO.sub.2 doped with Nb.
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Scotti Carlo
Visca Mario
Metz Andrew H.
Sibit S.p.A.
Wright William G.
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