Visible Light-Driven Z-Scheme Water Splitting Using Oxysulfide H2 Evolution Photocatalysts

Guijun Ma; Shanshan Chen; Yongbo Kuang; Seiji Akiyama; Takashi Hisatomi; Mamiko Nakabayashi; Naoya Shibata; Masao Katayama; Tsutomu Minegishi; Kazunari Domen

doi:10.1021/acs.jpclett.6b01802

Visible Light-Driven Z-Scheme Water Splitting Using Oxysulfide H₂ Evolution Photocatalysts

J Phys Chem Lett. 2016 Oct 6;7(19):3892-3896. doi: 10.1021/acs.jpclett.6b01802. Epub 2016 Sep 21.

Authors

Guijun Ma^{1

2}, Shanshan Chen^{1

2}, Yongbo Kuang^{1

2}, Seiji Akiyama³, Takashi Hisatomi^{1

2}, Mamiko Nakabayashi⁴, Naoya Shibata⁴, Masao Katayama^{1

2}, Tsutomu Minegishi^{1

2}, Kazunari Domen¹

Affiliations

¹ Department of Chemical System Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
² Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem), 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
³ Mitsubishi Chemical Group Science and Technology Research Center Inc., 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa 227-8502, Japan.
⁴ Institute of Engineering Innovation, The University of Tokyo , 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.

PMID: 27626912
DOI: 10.1021/acs.jpclett.6b01802

Abstract

A Sm₂Ti₂S₂O₅ (STSO) oxysulfide photocatalyst prepared by a novel flux method showed a higher degree of crystallinity and greater photocatalytic activity than that prepared by conventional polymerized complex and sulfurization processes. Co-loading with both IrO₂, as an oxidative cocatalyst, and Pt, as a reductive cocatalyst, was found to be essential for promoting the photocatalytic activity of the STSO. Visible light-driven Z-scheme water splitting into H₂ and O₂ was realized by utilizing the STSO photocatalyst for H₂ evolution in conjunction with a WO₃ photocatalyst treated with H⁺ and Cs⁺ and loaded with PtO_x for O₂ evolution, and a triiodide/iodide (I₃^-/I^-) redox couple as a shuttle electron mediator. Various other narrow band gap oxysulfide photocatalysts with H₂ evolution activity, such as La₅Ti₂CuS₅O₇ and La₆Ti₂S₈O₅, were also shown to be applicable as H₂ evolution photocatalysts in the present Z-scheme water splitting system.