Nitrogen‐Doped Engineering in Covalent Organic Frameworks for Photocatalytic Synthesis of Hydrogen Peroxide^†

Comprehensive Summary Photocatalytic synthesis of hydrogen peroxide (H 2 O 2 ) from air and water presents a sustainable and efficient alternative to the traditional anthraquinone method. Therefore, the design and synthesis of efficient photocatalysts for H 2 O 2 production are important. In this work, we apply a nitrogen‐site engineering strategy to achieve high‐performance photocatalysts by synthesizing three imine‐ linked oligo(phenylenevinylene)‐based covalent organic frameworks (OPV‐COFs) doped with different numbers of nitrogen atoms (denoted as COF‐920‐ n N, n = 0, 1, 3). Comprehensive characterization confirmed the high crystallinity and porosity of the COFs, critical for efficient photocatalysis. Each OPV‐COF exhibited the ability to rapidly synthesize H 2 O 2 using air and water, with COF‐920‐1N achieving the highest rate of 4288 μmol·g –1 ·h –1 under visible light, higher than those of most of other reported COFs. Mechanism studies demonstrated that the introduction of pyridine nitrogen atoms at the junction changes the electronic structure and electron transfer path within the COFs, enhancing the photogenerated electron mobility and reducing the rate of electron‐hole recombination. This study not only pioneers the class of OPV‐COFs for photocatalytic synthesis of H 2 O 2 , but also sets a foundational strategy for the rational design of COFs in photocatalytic applications.