Interfacial Active Sites in Bimetallic AgCuO‐Supported Graphdiyne for Highly Efficient Hydrogen Evolution Reaction

Abstract To replace rare and expensive precious metals, developing an electrocatalyst that combines cost‐effectiveness, stability, and enhanced efficiency for hydrogen evolution reactions (HER) remains a major challenge. In this study, graphdiyne with in situ formation of CuO nanoparticles is prepared using a simple one‐pot method, followed by the photodeposition of silver (Ag) under varying light exposure durations. Interestingly, GDY/Cu/Ag _{10min/0 °C} demonstrated outstanding HER activity, with a reduced onset overpotential of 193 mV and a Tafel slope of 84 mV dec ⁻¹ . This performance rivals or surpasses that of many reported non‐precious metal catalysts. The enhanced catalytic activity is attributed to a more accessible active site, resulting from the size reduction of Ag particles and the synergistic effect localized at the Cu/Ag interface. In particular, it is found that the Cu/Ag interface plays a pivotal role in the proton adsorption, which significantly enhances HER performance. Theoretical calculations revealed that proton adsorption at the Cu/Ag interface is significantly improved. Notably, the active sites at the Cu/Ag interface exhibited lower free adsorption energies (0.22–0.24 eV), resulting in lower limiting potential, in agreement with HER activity. The catalyst exhibits excellent performance, remarkable stability, and high efficiency, meeting the requirements for hydrogen production in diverse applications.