Electronic and magnetic properties of graphene absorbed with S atom: A first-principles study

Stable configuration, electronic structures, and magnetic behaviors for S adsorption on graphene have been investigated by first-principles calculations. It is found that the adsorption site of S on graphene is coverage dependent. As the increase in coverage from 0 to 0.5 ML, the preferred site is changed from bridge to hollow site. For the adsorption of S at bridge site, no magnetic moment is detected, and the adsorption is characterized by strong hybridization between the S 2s state and graphene sigma states. For the adsorption of S at hollow site, a magnetic moment of 1.98 mu(B) was induced. In this case, the hybridization occurs between S 2p states and graphene pi states. Furthermore, from the investigation of the surface potential energy curve, we find that graphene is a suitable candidate for the S storage.