Hydrogen sulfide molecule adsorbed on doped graphene: a first-principles study.

First principles were used to investigate electronic properties of Au-doped graphene, Ag-doped graphene, and Cu-doped graphene and the effect of adsorption behavior of hydrogen sulfide (H2S) molecule on their electronic properties. Doped graphene exhibits interesting electronic properties. The gap value of Ag-doped graphene is 0.29 eV, whereas Au-doped graphene is 0.48 eV which is the largest one in three doped systems, a clear difference of structure and electronic properties among three doped systems absorbing H2S molecule. The doped atom and the H2S molecule are on the same side of the graphene for Au-doped graphene and Cu-doped graphene, which belong to a kind of bonding orbital hybridization of electron cloud showed from charge difference density plots. However, Ag-doped graphene adsorbed with H2S molecule exhibits a kind of antibonding orbital hybridization. With the analysis in this paper, it is beneficial to research H2S gas sensors.