Covalent organic frameworks (COFs) are promising photocatalysts for H2O2 production from water via oxygen reduction reactions (ORR). The design of COFs for efficient H2O2 production indubitably hinges on an in‐depth understanding of their ORR mechanisms. In this work, taking an imine‐linked COF as an example, we demonstrate that protonation of the functional units such as imine, amine, and triazine, is a highly efficient strategy to upgrade the activity levels for H2O2 synthesis. The protonation not only extends the light absorption of the COF but also provides proton sources that directly participate in H2O2 generation. Notably, the protonation simplifies the reaction pathways of ORR to H2O2, i.e. from an indirect superoxide radical ([[EQUATION]]) mediated route to a direct one‐step two‐electron route. Theoretical calculations confirm that the protonation favors H2O2 synthesis due to easy access of protons near the reaction sites that removes the energy barrier for generating *OOH intermediate. These findings not only extend the mechanistic insight into H2O2 photosynthesis but also provide a rational guideline for the design and upgradation of efficient COFs.

中文翻译：

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亚胺连接的共价有机框架的质子化，在 700 nm 可见光下实现高效 H2O2 光合作用

共价有机框架 (COF) 是一种很有前途的光催化剂，可通过氧还原反应 (ORR) 从水中生产 H2O2。毫无疑问，用于高效生产 H2O2 的 COF 的设计取决于对其 ORR 机制的深入了解。在这项工作中，以亚胺连接的COF为例，我们证明了亚胺、胺和三嗪等功能单元的质子化是提高H2O2合成活性水平的高效策略。质子化不仅扩大了COF的光吸收，而且提供了直接参与H2O2生成的质子源。值得注意的是，质子化简化了 ORR 到 H2O2 的反应途径，即从间接超氧自由基（[[方程]]）介导的途径到直接的一步双电子途径。理论计算证实，质子化有利于 H2O2 的合成，因为质子很容易接近反应位点附近，从而消除了生成 *OOH 中间体的能量势垒。这些发现不仅扩展了对 H2O2 光合作用机制的认识，而且为高效 COF 的设计和升级提供了合理的指导。