title: Photoreduction of water by using modified CuInS2 electrodes.
abstract: Polycrystalline CuInS(2) films were fabricated by sulfurization of electrodeposited Cu and In metallic precursor films. Structural analyses revealed that the CuInS(2) film formed compact agglomerates of crystallites with grain sizes of ca. 0.5-1.5 μm. Photoelectrochemical characterization revealed that the film was p-type with a flat band potential of 0.3-0.4 V (vs Ag/AgCl at pH 4), which is suitable for water reduction but cannot be for water oxidation. Upon loading Pt deposits, the film worked as a hydrogen (H(2)) liberation electrode under cathodic polarization. Moreover, by introduction of n-type thin layers such as CdS and ZnS on the CuInS(2) surface before the Pt loading, appreciable improvements of H(2) liberation efficiency were achieved: for the CdS modified sample, spectral response data showed incident photon to current efficiency as high as 20 % at wavelengths ranging from ca. 500 to 750 nm. Appreciable H(2) evolution on this sample under potentials of power-producing regions was also confirmed.
authors.affiliation: Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka 560-8531, Japan. sikeda@chem.es.osaka-u.ac.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ikeda
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakamura
authors.forename: Sun Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Yagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Harada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Minegishi
authors.forename: Michio
authors.initials: M
authors.lastname: Matsumura
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006859:Hydrogen / Q000737:chemistry; D007204:Indium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods*; D010782:Photolysis; D013440:Sulfides / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D013440:Sulfides; D017967:Zinc Compounds; D007204:Indium; D014867:Water; D003300:Copper; D006859:Hydrogen; C031238:zinc sulfide