Efficient and stable visible-light-driven Z-scheme overall water splitting using an oxysulfide H2 evolution photocatalyst

Lihua Lin; Yiwen Ma; Junie Jhon M Vequizo; Mamiko Nakabayashi; Chen Gu; Xiaoping Tao; Hiroaki Yoshida; Yuriy Pihosh; Yuta Nishina; Akira Yamakata; Naoya Shibata; Takashi Hisatomi; Tsuyoshi Takata; Kazunari Domen

doi:10.1038/s41467-024-44706-4

Efficient and stable visible-light-driven Z-scheme overall water splitting using an oxysulfide H₂ evolution photocatalyst

Nat Commun. 2024 Jan 9;15(1):397. doi: 10.1038/s41467-024-44706-4.

Authors

Lihua Lin¹, Yiwen Ma¹, Junie Jhon M Vequizo¹, Mamiko Nakabayashi², Chen Gu¹, Xiaoping Tao¹, Hiroaki Yoshida^{3

4}, Yuriy Pihosh⁵, Yuta Nishina⁶, Akira Yamakata⁷, Naoya Shibata², Takashi Hisatomi¹, Tsuyoshi Takata¹, Kazunari Domen^{8

9}

Affiliations

¹ Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, Japan.
² Institute for Engineering Innovation, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
³ Science and Innovation Center, Mitsubishi Chemical Corporation, Aoba-ku, Yokohama-shi, Kanagawa, Japan.
⁴ Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem), Tokyo, Japan.
⁵ Office of University Professors, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
⁶ Graduate School of Natural Science and Technology, Okayama University, Kita-ku, Okayama, Japan.
⁷ Faculty of Natural Science and Technology, Okayama University, Kita-ku, Okayama, Japan.
⁸ Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano, Japan. domen@chemsys.t.u-tokyo.ac.jp.
⁹ Office of University Professors, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. domen@chemsys.t.u-tokyo.ac.jp.

Abstract

So-called Z-scheme systems permit overall water splitting using narrow-bandgap photocatalysts. To boost the performance of such systems, it is necessary to enhance the intrinsic activities of the hydrogen evolution photocatalyst and oxygen evolution photocatalyst, promote electron transfer from the oxygen evolution photocatalyst to the hydrogen evolution photocatalyst, and suppress back reactions. The present work develop a high-performance oxysulfide photocatalyst, Sm₂Ti₂O₅S₂, as an hydrogen evolution photocatalyst for use in a Z-scheme overall water splitting system in combination with BiVO₄ as the oxygen evolution photocatalyst and reduced graphene oxide as the solid-state electron mediator. After surface modifications of the photocatalysts to promote charge separation and redox reactions, this system is able to split water into hydrogen and oxygen for more than 100 hours with a solar-to-hydrogen energy conversion efficiency of 0.22%. In contrast to many existing photocatalytic systems, the water splitting activity of the present system is only minimally reduced by increasing the background pressure to 90 kPa. These results suggest characteristics suitable for applications under practical operating conditions.