Sulfur‐Deficient ZnIn2S4/Oxygen‐Deficient WO3 Hybrids with Carbon Layer Bridges as a Novel Photothermal/Photocatalytic Integrated System for Z‐Scheme Overall Water Splitting

• Published in: Advanced energy materials 2021-12, Vol.11 (46), p.n/a
• Main Authors: Wang, Yijin, Huang, Wenjing, Guo, Shaohui, Xin, Xu, Zhang, Youzi, Guo, Peng, Tang, Songwei, Li, Xuanhua
• Format: Article
• Language: English
• Subjects: Air masses; Carrier recombination; Chemical fuels; Current carriers; Electron transfer; electron transfer mediators; Light irradiation; Oxidation; Oxygen; Photocatalysis; Photocatalysts; photocatalytic systems; photothermal effect; reaction interface; Solar energy conversion; Sulfur; Water; Water splitting
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202102452

Although photocatalytic overall water splitting is a potential technology for converting solar energy into chemical fuel, the widely reported solar‐to‐hydrogen efficiency is around 1%, indicating unsatisfactory photocatalytic performance. Here, a novel photocatalyst material is designed and a whole reaction system is constructed, resulting in an integrative photothermal–photocatalytic Z‐scheme overall water splitting reaction system. In terms of materials design, a novel sulfur‐deficient ZnIn2S4/oxygen‐deficient WO3 (ZIS–WO) hybrid with surface‐carbonized wood (C‐wood) is reported. The ZIS–WO hybrid with sulfur and oxygen vacancies promotes the adsorption of visible light and the separation of charge carriers. The conductive C‐wood is strategically used as an additional electron bridge to accelerate electron transfer. In terms of system construction, the C‐wood exploits the photothermal effect to change the solid/liquid/gas triphase system to a solid/gas biphase system by transforming liquid water into steam, which drastically restrains carrier recombination, and decreases the photocatalytic reaction barrier. The H2 and O2 production rates in the proposed system are approximately 169.2 and 82.5 µmol h–1 under air mass (AM) 1.5 light irradiation, and the corresponding solar‐to‐hydrogen efficiency is as high as 1.52%. The study from photocatalyst design to reaction system construct opens a new insight for versatile and high‐performance photocatalytic overall water splitting. A high‐performance and scalable photothermal/photocatalytic Z‐scheme overall water splitting reaction system composed of a novel photocatalyst (sulfur‐deficient ZnIn2S4/oxygen‐deficient WO3 with surface‐carbonized wood is reported. Under the synthetic effects of a novel materials design and a whole reaction system construct, a high solar‐to‐hydrogen efficiency of 1.52% is achieved.