Modulating the electronic properties and hydrogen evolution reaction performance of precious-metal on 2D-SiC via surface defects

Abstract

2D-SiC exhibits considerable potential for optoelectronic applications. However, its intrinsic electronic structure limits its broader applicability, particularly in electrocatalytic hydrogen evolution reaction (HER) research, which remains underexplored. In this study, we employed first-principles calculations to systematically investigate the binding strength, electronic properties, magnetic characteristics, and HER performance of precious-metal (PM = Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au) single-atom catalysts (SACs) supported on vacancy-defective 2D-SiC. Our findings reveal that the binding strength and HER performance of PM single atoms supported at the Si-vacancy are markedly superior to those supported at the C-vacancy. Within Si-vacancy-supported PM systems, the binding strength of the PM on 2D-SiC increases with higher doping concentrations. Analysis of the HER activity for Pd and Pt-SACs at the Si-vacancy indicates that, within the same PM-supported system, a greater distance between the d-band-center and the Fermi level correlates with enhanced HER activity. Notably, Pt-SACs supported at the Si-vacancy in a 3 × 3 × 1 2D-SiC supercell exhibit excellent thermal stability and outstanding HER performance. In addition, the PM-SACs supported on vacancy-defective 2D-SiC display rich electronic and magnetic properties, and magnetic contribution analysis demonstrates that Si atoms do not contribute to the magnetism of the supported systems. These findings provide theoretical insights for the future application of 2D-SiC in electronic devices and electrocatalytic materials.