Photosynthesis of hydrogen peroxide (H₂O₂) from H₂O and O₂ is considered to be a promising approach. However, limited to the rapid recombination of photo-generated carriers and sluggish kinetics of O₂ reduction to H₂O₂, it is a challenge for polymeric photocatalysts to achieve efficient photocatalytic H₂O₂ production. Herein, Ag single atoms and nitrogen defects decorated carbon nitride (Ag@MCT) are constructed through self-assembly and pyrolysis methods. The optimized photocatalyst displays exceptional performance in pure water, with an H₂O₂ production rate of as high as 528.4 μmol g^-1 h^-1 and an apparent quantum yield for H₂O₂ production of 4.5% at 420 nm. Experimental and theoretical results reveal that the Ag atomic sites act as electron mediators that promote the capture and transfer of photo-generated charge carriers, while nitrogen defects as electron collectors and reaction sites to enhance the adsorption and activation of O₂, accelerating reduction kinetics from O₂ to H₂O₂. This work presents a reliable strategy to design excellent photocatalysts by rationally modulating electronic structures and active sites for accelerating photo-generated charge carriers transfer and surface reaction kinetics.

中文翻译：

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在氮化碳上构建 Ag 单原子和氮缺陷的不对称双活性位点，以增强光催化 H2O2 的产生


从 H₂、O 和 O₂ 光合作用过氧化氢 （H₂O₂） 被认为是一种很有前途的方法。然而，受限于光生载流子的快速复合和 O₂ 还原为 H₂O₂ 的缓慢动力学，聚合物光催化剂实现高效的光催化 H₂O₂ 生产是一个挑战。在此，Ag 单原子和氮缺陷修饰的氮化碳 （Ag@MCT） 是通过自组装和热解方法构建的。优化的光催化剂在纯水中表现出卓越的性能，H₂O₂ 生成速率高达 528.4 μmol ^{g-1 h-1}，在 420 nm 处产生 H₂O₂ 的表观量子产率为 4.5%。实验和理论结果表明，Ag 原子位点充当电子介质，促进光生载流子的捕获和转移，而氮缺陷作为电子收集器和反应位点，增强 O₂ 的吸附和活化，加速从 O₂ 到 H₂O₂ 的还原动力学.这项工作提出了一种可靠的策略，通过合理调节电子结构和活性位点来设计优秀的光催化剂，以加速光生载流子转移和表面反应动力学。