title: Photocatalytic CO2reduction using water as an electron donor by a powdered Z-scheme system consisting of metal sulfide and an RGO-TiO2composite.
abstract: CuGaS2, (AgInS2)x-(ZnS)2-2x, Ag2ZnGeS4, Ni- or Pb-doped ZnS, (ZnS)0.9-(CuCl)0.1, and ZnGa0.5In1.5S4showed activities for CO2reduction to form CO and/or HCOOH in an aqueous solution containing K2SO3and Na2S as electron donors under visible light irradiation. Among them, CuGaS2and Ni-doped ZnS photocatalysts showed relatively high activities for CO and HCOOH formation, respectively. CuGaS2was applied in a powdered Z-scheme system combining with reduced graphene oxide (RGO)-incorporated TiO2as an O2-evolving photocatalyst. The powdered Z-scheme system produced CO from CO2in addition to H2and O2due to water splitting. Oxygen evolution with an almost stoichiometric amount indicates that water was consumed as an electron donor in the Z-schematic CO2reduction. Thus, we successfully demonstrated CO2reduction of artificial photosynthesis using a simple Z-scheme system in which two kinds of photocatalyst powders (CuGaS2and an RGO-TiO2composite) were only dispersed in water under 1 atm of CO2.
authors.affiliation: Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. a-kudo@rs.kagu.tus.ac.jp.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Takayama
authors.forename: Ko
authors.initials: K
authors.lastname: Sato
authors.forename: Takehiro
authors.initials: T
authors.lastname: Fujimura
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kojima
authors.forename: Akihide
authors.initials: A
authors.lastname: Iwase
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kudo