Hydrogen adsorption on Ca-decorated epoxy-coating graphene

The hydrogen adsorption of calcium-decorated epoxy-doped graphene has been studied by density functional theory calculations. Several models are set up and the optimized geometries are obtained. The interaction among epoxy functional groups, graphene and metal atoms is studied by analyzing the electronic and band structures of the relaxed models. Mulliken population and the partial density of states are calculated to probe the nature of hydrogen molecules adsorption on this system. Our results demonstrate that this kind of stable material can be used as a promising hydrogen storage material.