Irfan Rana Muhammad, Jiang Daochuan, Sun Zijun, Lu Dapeng, Du Pingwu
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.
Dalton Trans. 2016 Aug 9;45(32):12897-905. doi: 10.1039/c6dt02148d.
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.
通过水分解进行光催化产氢因其在未来清洁能源应用中的潜力而备受关注。在此，我们报道了一种无贵金属的光催化产氢体系，该体系包含一种简单的双齿钴席夫碱配合物作为分子助催化剂、硫化镉纳米棒作为光敏剂以及抗坏血酸作为电子供体。与纯硫化镉纳米棒相比，该体系在可见光（λ > 420 nm）下表现出高度增强的光催化活性。在最佳条件下，光照12小时后产氢的周转数（TONs）达到约15200，在420 nm单色光下实现了约27%的表观量子产率。稳态光致发光（PL）光谱表明，激发态的硫化镉纳米棒与钴助催化剂之间发生了有效的电荷转移，从而提高了产氢效率。光催化反应的光谱研究揭示了Co(ii)配合物还原为Co(i)物种，这可能是析氢的活性中间体。基于光谱研究，我们提出了当前光催化体系中产氢的反应机理。
