Photocatalysis has become a sustainable way to produce hydrogen peroxide (H2O2), but poor carrier utilization and low productivity limit practical applications. Selecting a suitable proton donor to increase photocatalytic H2O2 production meanwhile producing valuable organic compounds could reduce hole (h+) oxidation ability waste and production costs. Here, benzyl alcohol (BA) is employed as a unique proton donor for selective dehydrogenation to generate benzaldehyde (BAL), while coupling and promoting the generation of H2O2. Surprisingly, the hollow nanoflower Zn3In2S6 with S vacancies provide excellent co-production performance of H2O2 and BAL with 67.6 and 96.19 mmol h−1 g−1 under visible light, respectively. Moreover, no by-products were observed in the reaction system due to the excellent moderate oxidation ability of 1O2, resulting in a high selectivity of 99.9 % for BAL and a conversion rate of 66.7 % for BA. Based on the results of free radical scavenging experiments, ESR, In-situ DRIFTS, and DFT calculations, the reaction mechanism and pathways were discussed in detail. Oxygen is converted into reactive oxygen species (ROS: ·O2– and 1O2) on the catalyst surface, and interacts with photo generated charge carriers and proton donors (BA) to promote the photocatalytic synthesis of H2O2 and BAL in solution. Overall, this work provides insights for the further development of new reactions, namely the effective utilization of photogenerated electrons and holes through defect and morphology control of the Zn3In2S6 system for photocatalytic oxidation of BA and precipitation of H2O2.

中文翻译：

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具有硫空位的 Zn3In2S6 空心纳米花：H2O2 和苯甲醛的高效光催化共产


光催化已成为生产过氧化氢 （H2O2） 的一种可持续方法，但载流子利用率低和生产率低限制了实际应用。选择合适的质子供体来增加光催化 H2O2 的产生，同时产生有价值的有机化合物可以减少空穴 （h+） 氧化能力、浪费和生产成本。在这里，苯甲醇 （BA） 被用作选择性脱氢生成苯甲醛 （BAL） 的独特质子供体，同时偶联并促进 H2O2 的产生。令人惊讶的是，具有 S 空位的空心纳米花 Zn3In2S6 在可见光下分别以 67.6 和 96.19 mmol h-1 g-1 提供了 H2O2 和 BAL 的优异共产性能。此外，由于 1O2 优异的中等氧化能力，在反应系统中未观察到副产物，因此 BAL 的选择性高达 99.9 %，BA 的转化率为 66.7 %。根据自由基清除实验、ESR、In-situ DRIFTS 和 DFT 计算的结果，详细讨论了反应机理和途径。氧气转化为活性氧 （ROS： ·O2– 和 1O2），并与光生电荷载流子和质子供体 （BA） 相互作用，促进溶液中 H2O2 和 BAL 的光催化合成。总的来说，这项工作为新反应的进一步开发提供了见解，即通过 Zn3In2S6 系统的缺陷和形态控制有效利用光生电子和空穴进行光催化氧化 BA 和 H2O2 沉淀。