Oxysulfide photocatalyst for visible-light-driven overall water splitting

Qian Wang; Mamiko Nakabayashi; Takashi Hisatomi; Song Sun; Seiji Akiyama; Zheng Wang; Zhenhua Pan; Xiong Xiao; Tomoaki Watanabe; Taro Yamada; Naoya Shibata; Tsuyoshi Takata; Kazunari Domen

doi:10.1038/s41563-019-0399-z

Oxysulfide photocatalyst for visible-light-driven overall water splitting

Nat Mater. 2019 Aug;18(8):827-832. doi: 10.1038/s41563-019-0399-z. Epub 2019 Jun 17.

Authors

Qian Wang^{1

2}, Mamiko Nakabayashi³, Takashi Hisatomi⁴, Song Sun^{5

6}, Seiji Akiyama^{7

8}, Zheng Wang⁴, Zhenhua Pan¹, Xiong Xiao^{8

9}, Tomoaki Watanabe⁹, Taro Yamada¹, Naoya Shibata³, Tsuyoshi Takata⁴, Kazunari Domen^{10

11}

Affiliations

¹ Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan.
² Department of Chemistry, University of Cambridge, Cambridge, UK.
³ Institute of Engineering Innovation, The University of Tokyo, Tokyo, Japan.
⁴ Center for Energy & Environmental Science, Shinshu University, Nagano, Japan.
⁵ School of Chemistry and Chemical Engineering, Anhui University, Anhui, China.
⁶ National Synchrotron Radiation Laboratory, Collaborative Innovation Center of Chemistry for Energy Materials, University of Science & Technology of China, Anhui, China.
⁷ Mitsubishi Chemical Corporation, Yokohama R&D center, Kanagawa, Japan.
⁸ Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem), Tokyo, Japan.
⁹ Department of Applied Chemistry, School of Science and Technology, Meiji University, Kanagawa, Japan.
¹⁰ Department of Chemical System Engineering, School of Engineering, The University of Tokyo, Tokyo, Japan. domen@chemsys.t.u-tokyo.ac.jp.
¹¹ Center for Energy & Environmental Science, Shinshu University, Nagano, Japan. domen@chemsys.t.u-tokyo.ac.jp.

PMID: 31209390
DOI: 10.1038/s41563-019-0399-z

Abstract

Oxysulfide semiconductors have narrow bandgaps suitable for water splitting under visible-light irradiation, because the electronegative sulfide ions negatively shift the valence band edges of the corresponding oxides^1,2. However, the instability of sulfide ions during the water oxidation is a critical obstacle to simultaneous evolution of hydrogen and oxygen³. Here, we demonstrate the activation and stabilization of Y₂Ti₂O₅S₂, with a bandgap of 1.9 eV, as a photocatalyst for overall water splitting. On loading of IrO₂ and Rh/Cr₂O₃ as oxygen and hydrogen evolution co-catalysts, respectively, and fine-tuning of the reaction conditions, simultaneous production of stoichiometric amounts of hydrogen and oxygen was achieved on Y₂Ti₂O₅S₂ during a 20 h reaction. The discovery of the overall water splitting capabilities of Y₂Ti₂O₅S₂ extends the range of promising materials for solar hydrogen production.