Photocatalytic CO2 reduction using water as an electron donor by a powdered Z-scheme system consisting of metal sulfide and an RGO-TiO2 composite

Tomoaki Takayama; Ko Sato; Takehiro Fujimura; Yuki Kojima; Akihide Iwase; Akihiko Kudo

doi:10.1039/c6fd00215c

Photocatalytic CO₂ reduction using water as an electron donor by a powdered Z-scheme system consisting of metal sulfide and an RGO-TiO₂ composite

Faraday Discuss. 2017 Jun 2:198:397-407. doi: 10.1039/c6fd00215c.

Authors

Tomoaki Takayama¹, Ko Sato, Takehiro Fujimura, Yuki Kojima, Akihide Iwase, Akihiko Kudo

Affiliation

¹ 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.

PMID: 28287650
DOI: 10.1039/c6fd00215c

Abstract

CuGaS₂, (AgInS₂)_x-(ZnS)_2-2x, Ag₂ZnGeS₄, Ni- or Pb-doped ZnS, (ZnS)_0.9-(CuCl)_0.1, and ZnGa_0.5In_1.5S₄ showed activities for CO₂ reduction to form CO and/or HCOOH in an aqueous solution containing K₂SO₃ and Na₂S as electron donors under visible light irradiation. Among them, CuGaS₂ and Ni-doped ZnS photocatalysts showed relatively high activities for CO and HCOOH formation, respectively. CuGaS₂ was applied in a powdered Z-scheme system combining with reduced graphene oxide (RGO)-incorporated TiO₂ as an O₂-evolving photocatalyst. The powdered Z-scheme system produced CO from CO₂ in addition to H₂ and O₂ due to water splitting. Oxygen evolution with an almost stoichiometric amount indicates that water was consumed as an electron donor in the Z-schematic CO₂ reduction. Thus, we successfully demonstrated CO₂ reduction of artificial photosynthesis using a simple Z-scheme system in which two kinds of photocatalyst powders (CuGaS₂ and an RGO-TiO₂ composite) were only dispersed in water under 1 atm of CO₂.

Publication types

Research Support, Non-U.S. Gov't