▎ 摘　　要

Sulphur dioxide (SO2) is a corrosive and irritating gas that can cause serious damage to human health and natural environment. Therefore, designing effective gas sensors to detect and remove SO2 is urgent. The adsorption properties of SO2 on the graphene, N-doped, Ti-doped, and N-Ti co-doped graphene (N-G, Ti-G and N-Ti-G) are investigated. Our results based on the density functional theory show that SO2 molecules can stably chemically adsorb on Ti-G and N-Ti-G. The lowest adsorption energy (-2.836 eV) and remarkable charge transfer (0.735 e move from N-Ti-G to SO2) indicate the N-Ti-G is the optimal adsorbent. Biaxial strain can effectively adjust the adsorption characters and external electric field can enhance the stability of adsorption. Physical adsorption is formed between SO2 and graphene/N-G due to weak interactions. Our work provides a valuable theoretical guidance for the development of N-Ti-G substrate as promise gas sensor to detection and removal of SO2.