Trinuclear Copper‐Cluster‐Bridged Covalent Organic Framework with Synergistic Zinc Single Atoms for Photocatalytic Hydrogen Evolution

Efficient and stable photocatalytic water splitting catalysts based on platinum‐free nonprecious metals offer a promising approach to solar‐driven hydrogen production. Here, we synthesized a covalent organic framework (COF) featuring a trinuclear copper cluster (Cu 3 ‐BPY‐COF) and constructed a platinum‐free bimetallic photocatalyst (Cu 3 ‐BPY‐COF(Zn)) through the coordination of Zn 2+ via bipyridine. Cu 3 ‐BPY‐COF(Zn) achieves a hydrogen production rate of 23.04 mmol g −1 h −1 under visible light ( λ > 420 nm), which is a significant improvement over unmodified Cu 3 ‐BPY‐COF (11.60 mmol g −1 h −1 ), and ranks among the best nonprecious metal photocatalysts up to now. The catalyst maintains performance stability for over 32 h with an apparent quantum efficiency of 15.2%. Experimental results and theoretical calculations suggest that the Cu 3 cluster serves as an efficient electron transfer pathway, while Zn 2+ coordination optimizes the electronic structure of the bipyridine ligand, facilitating charge separation and migration. The synergistic effect of Cu 3 –Zn promotes H 2 production by modulating the adsorption free energy of H intermediates, enabling highly efficient proton reduction and thereby achieving high HER activity. This study presents a novel approach for designing platinum‐free bimetallic photocatalysts based on COF for efficient hydrogen production.