Patents Assigned to Sibit, S.p.A.
  • Catalysts for photo-assisted oxidation-reduction reactions
    Patent number: 4623437
    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.
    Type: Grant
    Filed: July 15, 1982
    Date of Patent: November 18, 1986
    Assignee: Sibit S.p.A.
    Inventors: Mario Visca, Carlo Scotti
  • Process for tanning hides
    Patent number: 4560384
    Abstract: A process for tanning hides for soles or insoles with ammonium titanyl sulphate. The hides, subjected to soaking, liming, fleshing, and deliming, are first treated with ammonium sulphate. Successively, ammonium titanyl sulphate as well as citric acid or an alkali metal citrate are gradually added to the bath, while maintaining the temperature of the bath at a value not exceeding 37.degree. C. and a pH at values ranging from 1.7 to 2.5. After each addition, the hides are treated until they have absorbed at least 90% of the soluble Ti (IV). Sodium sulphite and hexamethylenetetramine are then gradually added: this addition is such as to bring the final pH of the bath to 3.8-4.5 and to exhaust the bath in soluble Ti (IV). NaHCO.sub.3 is successively added until a pH value of the bath ranging from 4.0 to 5.0 is reached, such pH being maintained for at least 2 hours.
    Type: Grant
    Filed: June 7, 1984
    Date of Patent: December 24, 1985
    Assignees: Loris Guidi, Sibit S.p.A.
    Inventors: Sergio Vanni, Loris Guidi, Paolo Vallini, Renato C. Pace, Carlo Scotti
  • Catalyst for the photo-decomposition of water and process for the preparation of the catalyst
    Patent number: 4370263
    Abstract: The present invention concerns a catalyst for the photodecomposition of water. Said catalyst consists of particles of TiO.sub.2 doped with Nb, said particles containing RuO.sub.2 on their surface. This catalyst may be used, for instance, in combination with ruthenium trisbipyridyl, methylviologen and colloidal platinum.
    Type: Grant
    Filed: June 29, 1981
    Date of Patent: January 25, 1983
    Assignee: Sibit, S.p.A.
    Inventor: Mario Visca