First-principles study of gas molecule adsorption on Ga-doped silicene

Abstract In this paper, based on first-principles calculations, the geometric structure and electronic properties of intrinsic silicene and metal element Ga doped silicene were studied, and three harmful gases CO, SO 2 and NH 3 gas molecules and H 2 O molecules were analyzed in two adsorption properties on the surface of two material. For each gas molecule, the optimal adsorption site was tried and determined, and parameters such as adsorption distance, adsorption energy, transfer charge, recovery time, and density of states were calculated to understand the adsorption mechanism. It was found that the adsorption capacity of the selected gas molecules on intrinsic silicene was weak except for NH 3 . While Ga doped silicene is a relatively stable structure, the adsorption energies of CO, SO 2 and NH 3 gas molecules on its surface increase in different degrees, the adsorption energies are −0.51 eV, −0.82 eV and −0.73 eV, but no adsorption to H 2 O. The results show that the doping of Ga atoms improves the adsorption performance of silicene materials, and is less affected by the humidity in the air in practical applications, which provides a theoretical reference for the gas-sensing properties of Ga doped silicene materials.