Overall Water Splitting by a SrTaO2N-Based Photocatalyst Decorated with an Ir-Promoted Ru-Based Cocatalyst

Kaihong Chen; Jiadong Xiao; Junie Jhon M Vequizo; Takashi Hisatomi; Yiwen Ma; Mamiko Nakabayashi; Tsuyoshi Takata; Akira Yamakata; Naoya Shibata; Kazunari Domen

doi:10.1021/jacs.2c11025

Overall Water Splitting by a SrTaO₂N-Based Photocatalyst Decorated with an Ir-Promoted Ru-Based Cocatalyst

J Am Chem Soc. 2023 Feb 22;145(7):3839-3843. doi: 10.1021/jacs.2c11025. Epub 2023 Jan 20.

Authors

Affiliations

¹ Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano-shi, Nagano 380-8553, Japan.
² PRESTO, JST, 4-17-1 Wakasato, Nagano-shi, Nagano 380-8553, Japan.
³ Institute of Engineering Innovation, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.
⁴ Graduate School of Natural Science & Technology, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan.
⁵ Office of University Professors, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656, Japan.

Abstract

The development of narrow-bandgap photocatalysts for one-step-excitation overall water splitting (OWS) remains a critical challenge in the field of solar hydrogen production. SrTaO₂N is a photocatalytic material having a band structure suitable for OWS under visible light (λ ≤ 600 nm). However, the presence of defects in the oxynitride and the lack of cocatalysts to promote simultaneous hydrogen and oxygen evolution make it challenging to realize OWS using this material. The present work demonstrates a SrTaO₂N-based particulate photocatalyst for OWS. This photocatalyst, which was composed of single crystals, was obtained by nitriding SrCl₂ and Ta₂O₅ together with NaOH, with the latter added to control the formation of defects. The subsequent loading of bimetallic RuIrO_x nanoparticles accelerated charge separation and allowed the SrTaO₂N photocatalyst to exhibit superior OWS activity. This research presenting the strategies of controlling the oxygen sources and promoting the cocatalyst function is expected to expand the range of potential OWS-active oxynitride photocatalysts and permit the design of efficient cocatalysts for photocatalytic OWS.