A novel two-step electrodeposition method is presented to fabricate a high-performance CoS/graphene hybrid network with a nanosheet structure on Ni foam.

Developing diatomic catalysts (DACs) for the CO2 reduction reaction (CO2RR) has emerged as a promising leading-edge research area owing to their maximum atomic utility and more sophisticated functionalities. However, the proper design of DACs at an atomic level and an understanding of the synergistic mechanism of binary sites remain challenging. Herein, an N-rich carbon matrix with precisely controlled Ni/Cu dual sites is synthesized through the assistance of metal–organic frameworks. The as-prepared catalyst presents high CO Faradaic efficiency of over 95% from −0.39 to −1.09 V vs reversible hydrogen electrode (RHE) with the maximum value of 99.2% at −0.79 V vs RHE and long-term durability of 60 h electrolysis. Density functional theory studies reveal that the electronic redistribution and band gap narrowing induced by the adjacent NiN4 and CuN4 moieties enhance the electron conductivity and strengthen the bonding interactions between *COOH intermediates and Ni centers, thus lowering the overall reaction barriers and promoting CO generation.