Development of Novel Perovskite‐Like Oxide Photocatalyst LiCuTa3O9 with Dual Functions of Water Reduction and Oxidation under Visible Light Irradiation

• Published in: Advanced energy materials 2018-12, Vol.8 (35), p.n/a
• Main Authors: Dong, Beibei, Cui, Junyan, Liu, Taifeng, Gao, Yuying, Qi, Yu, Li, Deng, Xiong, Fengqiang, Zhang, Fuxiang, Li, Can
• Format: Article
• Language: English
• Subjects: Conduction bands; Density functional theory; Diffuse reflectance spectroscopy; Electromagnetic absorption; hydrogen; Light irradiation; Oxidation; oxide; Perovskites; Photocatalysis; Photocatalysts; Photochemical reactions; Reagents; Reduction; solar energy conversion; Valence band; Water splitting
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201801660

Development of new visible‐light‐responsive materials is highly desirable in photocatalysis. Here, a novel oxide material LiCuTa3O9 (LCTO) with a characteristic perovskite‐like structure, exhibiting a visible light absorption edge of ≈500 nm due to the hybridization of Cu 3d and O 2p orbitals, is reported. The structure of the as‐obtained LCTO is experimentally characterized and theoretically simulated. UV–vis diffuse reflectance spectroscopy, Mott–Schottky, and density functional theory calculation results show that the LCTO is an n‐type semiconductor with bandgap of ≈2.48 eV and exhibits suitable conduction band and valence band positions of ≈−0.45 and 2.03 eV vs reversible hydrogen electrode, respectively. Based on initial optimization of preparative conditions and loading of cocatalysts, the as‐modified LCTO sample can drive both water reduction and oxidation half reactions in the presence of corresponding sacrificial reagents under visible light irradiation (λ ≥ 420 nm), demonstrating its promising application in solar water splitting. The dual functional features of LCTO render it a promising photocatalyst for one‐step overall water splitting to produce hydrogen. In addition, the unobvious structural change of the LCTO photocatalyst during the reaction and repeated runs of the photocatalytic H2 evolution reaction demonstrate its good photochemical stability. A novel characteristic perovskite‐like oxide material LiCuTa3O9 with a light absorption edge of ≈500 nm is synthesized to exhibit dual functions of water oxidation and reduction under visible light irradiation. The bifunctional features render it a promising candidate photocatalyst for one‐step overall water splitting to produce hydrogen.