Electron‐Deficient Single‐Molecule‐Junction Sites in COFs Enable H ₂ O ₂ Photosynthesis via Precision Charge Delivery and Oxygen Adsorption

Abstract

ABSTRACT Covalent organic frameworks (COFs) have emerged as a promising platform for photocatalytic H 2 O 2 production, a key reaction in artificial photosynthesis. However, the practical application of conventional benzene‐rich COF skeletons is often limited by their weak oxygen adsorption capacity and inefficient charge carrier transport. To address these challenges, we report a universal post‐synthetic strategy that incorporates local, electron‐deficient polar single‐molecule junctions into the COF framework via a straightforward one‐step modification. These engineered junctions play a dual role: the localized electron‐deficient sites strongly anchor and activate oxygen molecules, while the in‐built polarity establishes directional channels for the migration of photogenerated charge carriers, ensuring their precise delivery to active sites. This synergistic mechanism leads to a marked enhancement in superoxide radical generation and the subsequent synthesis of H 2 O 2 . Under acidic conditions (pH = 3), the H 2 O 2 generation rate of the monomolecularly‐linked COF reached 4354 µmol g −1 h −1 , significantly higher than the 1655 µmol g −1 h −1 of the pristine COF. The broad applicability of this design principle was firmly established through the successful implementation of a series of tailor‐made analogous molecules across several distinct COF platforms.