Strengthening strategy of interface strength of silver-coated copper nanomaterials: Comprehensive exploration based on first-principles calculations

Silver-coated copper nanomaterials demonstrate enhanced catalytic activity in electrochemical CO 2 reduction through interfacial electron transfer effects that optimize adsorption strength. However, the interfacial binding mechanism and strategies for enhancing binding strength remain unclear due to insufficient systematic studies. In this study, we systematically investigate the mechanical properties of the Cu–Ag system, encompassing both pure metals and intermetallic compounds, through comprehensive computational analysis of their elastic, hardness, anisotropy, Poisson’s ratio, etc. Thermodynamic calculations demonstrate the instability of both Cu 3 Ag and CuAg 3 intermetallic phases, confirming that the interfaces in silver-coated copper nanoparticles are composed of pure Cu and Ag. Subsequent computational studies focus on low-index crystalline surfaces (100), (110), (111), (101), and (001) of pure Cu and Ag. Surface energy and work of adhesion calculations reveal that the (111) interface possesses the lowest energy, demonstrating that the Cu(111)/Ag(111) interface constitutes the most stable interfacial configuration. Substitution of a single Si atom at the interfacial site was found to enhance the interfacial strength. Density of states (DOS) and charge density difference analyses reveal significant charge transfer at the Cu/Ag interface, with reduced charge accumulation correlating to increased tensile strength. This study provides fundamental insights into the interfacial characteristics of silver-coated copper materials, offering guidance for designing high-performance catalytic systems.