Effect of Hydrogen Molecule Dissociation on Hydrogen Storage Capacity of Graphene with Metal Atom Decorated

Surface decoration with metal atoms is an efficient way to improve the hydrogen storage capacity of graphene. The hydrogen adsorption behavior on Al-decorated graphene is studied based on first-principles calculations. The dissociation of hydrogen molecule adsorbed on Al-decorated graphene is revealed, and its effect on the hydrogen storage capacity is investigated. Moreover, the effects of B-dopant on the dispersion of Al atoms on graphene and the dissociation behavior of hydrogen molecules are also studied. Our results indicate that hydrogen dissociation behavior has a significant effect on the hydrogen storage capacity of metal-decorated graphene and must be considered in the investigation of hydrogen storage behavior of metal-decorated carbon nanomaterials. Furthermore, through a comparison study on the hydrogen adsorption behavior on Li-, Ca-, and Al-decorated graphene, the factors relating to the hydrogen molecule dissociation are revealed.