Patents Assigned to Michael Graetzel
  • Product intended to be used as a photocatalyst, method for the preparation of such product and utilization of such product
    Patent number: 4427749
    Abstract: The product is in the form of discrete particles or in the form of a layer comprising an electrode. It consists of a semi-conductor material subject to photo-corrosion, for example, cadmium sulphide. In order to prevent such photo-corrosion, the surface of the semi-conductor material, which is intended to be illuminated, is covered with a transparent layer of RuO.sub.2, IrO.sub.2 or a mixture of RuO.sub.2 and IrO.sub.2.The product may be used for the conversion of solar energy into electric energy or into a fuel such as hydrogen.
    Type: Grant
    Filed: January 27, 1982
    Date of Patent: January 24, 1984
    Assignee: Michael Graetzel
    Inventors: Michael Graetzel, Kuppuswamy Kalyanasundaram, Dung Duonghong, Michael Neumann-Spallart, Enrico Borgarello
  • Method for producing hydrogen and elemental sulphur by photochemical oxidation-reduction of hydrogen sulphide and metal sulphides
    Patent number: 4405424
    Abstract: Hydrogen and elemental sulphur are produced by irradiation by visible light of solutions of hydrogen sulphide or of metal sulphides in presence of a catalyst consisting of a semiconductor material, such as cadmium sulphide, coated with a transparent layer of ruthenium oxide.
    Type: Grant
    Filed: May 28, 1982
    Date of Patent: September 20, 1983
    Assignee: Michael Graetzel
    Inventors: Michael Graetzel, Kuppuswamy Kalyanasundaram, Enrico Borgarello, Ezio Pelizzetti