It is widely accepted that photogenerated holes are the only driving force for oxidizing an electron donor to form H⁺ during photocatalytic H₂O₂ production (PHP). Here, we use nitrogen deficiency carbon nitride as a model catalyst and propose several different reaction mechanisms of PHP based on the comprehensive analysis of experiment and simulation results. Nitrogen vacancies can serve as a center for oxidation, reduction, and charge recombination, promoting the generation of h⁺, •O₂^–, and ¹O₂, respectively, and thus induce H₂O₂ generation through five different pathways. In particular, the ¹O₂ anchored on the catalyst surface can realize the indirect oxidation of isopropanol with the assistance of surrounding water molecules and produce H₂O₂ with the lowest barrier. This work proves that H₂O₂ can be generated through multiple pathways and highlights the main roles of ¹O₂, which are ignored by previous studies.

中文翻译：

---

具有氮空位的 g-C3N4 光催化 H2O2 生产中以活性氧物种为主的直接攻击和间接转移机制

人们普遍认为，光生空穴是在光催化 H ₂ O ₂生产 (PHP)过程中氧化电子供体形成 H ⁺的唯一驱动力。在此，我们以缺氮氮化碳为模型催化剂，在综合分析实验和模拟结果的基础上，提出了几种不同的PHP反应机理。氮空位可以作为氧化、还原和电荷复合的中心，分别促进h ⁺、•O ₂ ^–和¹ O _{2 的生成}，从而通过五种不同的途径诱导H ₂ O _{2 的}生成。特别是，锚定在催化剂表面的¹ O ₂可以在周围水分子的帮助下实现异丙醇的间接氧化，生成势垒最低的H ₂ O ₂。这项工作证明了 H ₂ O ₂可以通过多种途径产生，并突出了¹ O ₂的主要作用，而这在以前的研究中被忽略了。