title: Enhanced photocatalytic H2 production on CdS nanorods with simple molecular bidentate cobalt complexes as cocatalysts under visible light.
abstract: Photocatalytic hydrogen production via water splitting has attracted much attention for future clean energy application. Herein we report a noble-metal-free photocatalytic hydrogen production system containing a simple bidentate cobalt Schiff base complex as the molecular cocatalyst, CdS nanorods as the photosensitizer, and ascorbic acid as the electron donor. The system shows highly enhanced photocatalytic activity compared to pure CdS NRs under visible light (λ > 420 nm). Under optimal conditions, the turnover numbers (TONs) for hydrogen production reached ∼15 200 after 12 hours of irradiation, and an apparent quantum yield of ∼27% was achieved at 420 nm monochromatic light. Steady-state photoluminescence (PL) spectra indicated efficient charge transfer between the excited CdS NRs and the cobalt cocatalyst for improved hydrogen production. Spectroscopic studies of the photocatalytic reaction revealed the reduction of the Co(ii) complex to Co(i) species, which are probably active intermediates for hydrogen evolution. On the basis of the spectroscopic studies, we propose a reaction mechanism for hydrogen production in the present photocatalytic system.
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, P. R. China. dupingwu@ustc.edu.cn.
authors.forename: Rana Muhammad
authors.initials: RM
authors.lastname: Irfan
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, P. R. China. dupingwu@ustc.edu.cn.
authors.forename: Daochuan
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, P. R. China. dupingwu@ustc.edu.cn.
authors.forename: Zijun
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, P. R. China. dupingwu@ustc.edu.cn.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Lu
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, Department of Materials Science and Engineering, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui Province 230026, P. R. China. dupingwu@ustc.edu.cn.
authors.forename: Pingwu
authors.initials: P
authors.lastname: Du