DFT study on the selective adsorption properties of modified graphene for SF6 decompositions

In the paper, the adsorption of H2S on three modified graphene by doping Pd atom and introducing oxygen–containing functional groups (Pd–G, G–O and G–OH) was studied based on first principles. All the three modification methods improve the adsorption performance of graphene for H2S, among which the introduction of hydroxyl shows the best with the adsorption energy of −1.255eV. Nevertheless, Pd–G, G–O and G–OH exhibited similar adsorption properties for SO2, SO2F2, SOF2 and H2S, with the small difference of adsorption energy values. So the three modified graphene structures show poor selective adsorption performance for H2S. Then, the influence of the combine interaction of Pd atom and oxygen–containing functional group on the performance of graphene (Pd–G–O, Pd–G–OH) adsorbing H2S is further studied. Among them, the structure of Pd–G–O is stable, and the adsorption energy of Pd–G–O adsorbing H2S is −1.623eV. However, the adsorption energies of SO2, SO2F2 and SOF2 adsorbed on Pd–G–OH are −0.751eV, −0.799eV and −0.552eV, respectively. The excellent adsorption capacity of H2S on Pd–G–O is verified from the practical feasibility and selectivity. Therefore, Pd–G–O is a potential gas sensor material for selective adsorption of H2S.