Photoinduced Dynamic Electronic Asymmetry of Cu Dual‐Atom Sites Within Covalent Organic Frameworks Boosts Hydrogen Production

The development of efficient and cost‐effective alternatives to noble metal cocatalysts for photocatalytic hydrogen evolution remains a significant challenge. Herein, we demonstrate a facile strategy for constructing atomically dispersed dual Cu sites within a covalent organic framework (COF), using molecular carboxylic acids as coordinating ligands. Through in situ spectroscopic characterization and theoretical calculations, we identified a light‐induced dynamic electronic restructuring involving the reduction of one Cu(II) to Cu(I) within the dual‐atom site, generating a mixed‐valence state with asymmetric electronic configuration. This dynamic asymmetry facilitates electron transfer process and optimizes hydrogen intermediate adsorption. Enhanced H 2 generation is achieved, and the performance exceeds that of benchmark Pt cocatalyst. Furthermore, the molecular carboxylic acid‐assisted strategy employed here is successfully extended to improve the H 2 evolution activity of Pt. This work offers an applicable method for constructing dual‐atomic‐site catalysts and provides insights into dynamic active sites in catalysis.