Photocatalytic hydrogen evolution coupled with selective oxidation to produce fine chemicals under mild conditions is a promising strategy for green synthesis of both fuel carriers and useful materials. Herein, we report a highly efficient catalyst, created by in-situ anchoring cobalt nanoparticles onto cadmium sulfide nanorods, for simultaneous hydrogen evolution and benzaldehyde production from photocatalytic dehydrogenation of benzyl alcohol under visible light. Two half reactions, hydrogen evolution and benzaldehyde production, are well coupled as the reductive side and oxidative side, respectively. The system can produces hydrogen and benzaldehyde with high selectivity and efficiency. The optimal selectivity for benzaldehyde production is ∼94.4%. Mechanism studies indicate that the carbon-centered radical is the key intermediate during the oxidation of benzyl alcohol and plays a very important role on the selectivity for benzaldehyde production. Under optimal conditions, the rate of hydrogen evolution in the present noble-metal-free system is ∼848 µmol h⁻¹ and an apparent quantum yield of 63.2% (λ = 420 ± 5 nm) is achieved. To the best of our knowledge, this is the highest value ever reported for hydrogen evolution from photocatalytic dehydrogenation of benzyl alcohol under visible light.

光催化制氢和选择性氧化在温和条件下生产精细化学品是绿色合成燃料载体和有用材料的有前途的策略。本文中，我们报告了一种高效催化剂，该催化剂是通过将钴纳米颗粒原位锚固到硫化镉纳米棒上而产生的，用于同时在可见光下放出氢气和苯甲醇的光催化脱氢生产苯甲醛。氢气的逸出和苯甲醛的产生的两个半反应分别在还原侧和氧化侧都很好地耦合。该系统可以高选择性和高效率地生产氢气和苯甲醛。苯甲醛生产的最佳选择性约为94.4％。机理研究表明，以碳为中心的自由基是苯甲醇氧化过程中的关键中间体，对苯甲醛生产的选择性起着非常重要的作用。在最佳条件下，目前的无贵金属体系中氢的释放速率约为848 µmol·h^-1，表观量子产率达到63.2％（λ= 420±5 nm）。据我们所知，这是有史以来报道的在可见光下苯甲醇光催化脱氢制氢的最高值。