In this paper, based on density functional theory, the adsorption mechanism and gas sensitivity of Ag2O/CuO-modified SnS2 were analyzed. The results were analyzed according to the adsorption energy, total density of states, partial density of states, and frontier molecular orbital theory. The results show that the adsorption of all gas molecules is exothermic. NH3, Cl2, and C2H2 gases are chemisorbed on the modified SnS2 surfaces. After gas adsorption, the energy gap of the base changes by more than 10%, which fully shows that the conductivity changes greatly after gas adsorption, which can be reflected in the macroscopic resistance change. Ag2O-SnS2 is suitable as a gas sensor for NH3 gas sensors in terms of moderate adsorption distance, large adsorption energy, charge transfer, and frontier molecular orbital theory, while CuO-SnS2 is more suitable as a C2H2 gas sensor.
© 2022 The Authors. Published by American Chemical Society.