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.