Amidoxime‐Functionalized sp 2 ‐Carbon‐Conjugated Covalent Organic Frameworks for Overall Photocatalytic Hydrogen Peroxide Production

Abstract Cyano‐functionalized sp 2 ‐carbon‐conjugated covalent organic frameworks (CN‐COFs) have been considered as promising candidates for artificial photosynthesis of hydrogen peroxide (H 2 O 2 ). Nevertheless, the performance of CN‐COFs is inherently limited by constrained oxygen capture capacity, insufficient charge separation, and rapid carrier recombination. Herein, the study rationally reports a strategy for integrating amidoxime groups (AO) into a COF through one‐step cyano hydrolysis process to increase photocatalytic H 2 O 2 production. Combined simulations and characterizations reveal that introducing AO groups enhances hydrophilicity, stabilizes adsorbed Oxygen (O 2 ) via hydrogen bonding, accelerates the charge separation and transfer, as well as lowers the energy barrier for oxygen reduction reaction pathway, thus achieving an unmatched H 2 O 2 production rate of 6024 µmol h −1 g −1 . Importantly, the solar‐to‐chemical conversion (SCC) efficiency of PTTN‐AO reaches 0.61%, significantly surpassing that of natural plants (≈0.1%) and most COF‐based photocatalysts. The current findings are encouraging for the molecular design of polymers for green and efficient H 2 O 2 production.