▎ 摘　　要

The van der Waals (vdW) heterostructure combining different 2D materials stimulates broad research interests. Novel chemical and electronic properties can be obtained via building vdW heterostructures. In this paper, the CO2 adsorption properties of buckled honeycomb antimonene/graphene (hb-Sb/G) vdW heterostructure are examined by first-principles calculation, which provides theoretical insights into the enhanced electrocatalytic activity for CO2 reduction of hb-Sb/G heterostructure reported in a recent experimental study. Furthermore, by applying in-plane biaxial strains, the tunable Schottky barrier and transition of contact property are observed. As compressive strain decreases or tensile strain increases, the catalytic activity of hb-Sb/G heterostructure is predicted to be enhanced as a result of the increased interlayer coupling. Our work reveals the origin of electrocatalytic activity of hb-Sb/G heterostructure for CO2 reduction and proposes a strain engineering method to enhance its catalytic activity via tuning its electronic structure. This work uncovers promising applications of hb- Sb/G heterostructure in green energy and ultra-thin devices.