ABSTRACT 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.
Niu et al. (Sun,) studied this question.