DFT Study on the Selective Adsorption Properties of Modified Graphene for SF6 Decompositions

In the paper, the adsorption of H
₂
S 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 H
₂
S, 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 SO
₂
, SO
₂
F
₂
, SOF
₂
and H
₂
S, with the small difference of adsorption energy values. So the three modified graphene structures show poor selective adsorption performance for H
₂
S. 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 H
₂
S is further studied. Among them, the structure of Pd-G-O is stable, and the adsorption energy of Pd-G-O adsorbing H
₂
S is -1.623eV. However, the adsorption energies of SO
₂
, SO
₂
F
₂
and SOF
₂
adsorbed on Pd-G-OH are -0.751eV, -0.799eV and -0.552eV, respectively. The excellent adsorption capacity of H
₂
S 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 H
₂
S.