Hydrogenated graphene: Structures and surface work function

The structures and surface work functions of graphanes with five fundamental configurations are systematically studied with the density functional theory. We find that, from the point of view of energy, hydrogenated graphene prefer forming the chair graphane than the other ones. The work function and layer thickness of the five structures vary with the hydrogenation, providing important theoretical data for experimental identifying the configurations of graphanes by STM and AFM.