Building a Confluence Charge Transfer Pathway in COFs for Highly Efficient Photosynthesis of Hydrogen Peroxide from Water and Air

Sunlight‐driven photosynthesis by covalent organic frameworks (COFs) from water and air without using sacrificial reagents is a promising H2O2 fabrication approach, but is still restricted by the insufficient charge separation and sluggish 2e‐ water oxidation process. Herein, we provide a facile strategy to simultaneously improve charge separation and water oxidation in COFs via confining the charge transfer pathways from two diversion ones to a confluence one through regulating the site of nitrogen in bipyridine. Combining in‐situ characterization with computational calculations, we reveal that compared to COF‐BD1 containing two diversion charge transfer pathways, the charge transfer pathway in COF‐BD2 is confined to a confluence one due to the electron‐deficiency effect of nitrogen, which greatly accelerates the intermolecular and out‐of‐plane charge transfer. Via effectively reducing the energy barrier of rate‐determining water oxidation reaction, the subsequent water oxidation process to produce key *OH intermediate in COF‐BD2 is also greatly facilitated, boosting the yield of H2O2 (5211 μmol g‐1 h‐1) from water, oxygen, and light without sacrificial agents or additional energy consumption. We further demonstrate that H2O2 can be efficiently produced by COF‐BD2 in broad pH range, in real water, and in enlarged reactor with using natural sunlight for water decontamination.