▎ 摘　　要

The effect of Co-doped (CoG), Ti-doped (IG-Ti), and Co-Ti co-doped (CoG-Ti) graphene on the adsorption of SO2 molecules has been investigated by first-principle calculations. The stability of the material was demonstrated by the binding energy, cohesion energy, and first-principles molecular dynamics of the three graphene-based structures. By analyzing the structures and electronic properties at different adsorption sites, it can be demon-strated that the adsorption performance of the doped graphene for SO2 is better than that of IG. The adsorption distances of CoG (2.037 angstrom), IG-Ti (1.972 angstrom) and CoG-Ti (2.006 angstrom) for SO2 are significantly smaller than those of IG for the gas (3.476 angstrom). CoG-Ti has the best adsorption performance for SO2 because its adsorption energy (-4.635 eV) is higher than that of CoG (-3.471 eV) and IG-Ti (-4.519 eV) and its charge transfer (2.610 e) is higher than that of CoG (1.856 e) and IG-Ti (2.528 e). And the peak of the CoG-Ti adsorbed gas at the Fermi energy level increases, the hybridization degree of the fractional density of states is large, the band gap of the energy band is opened, and the number of energy bands at the Fermi energy level increases a lot. These results provide new possibilities for graphene to improve the adsorption of gases by doping with transition metals.