▎ 摘　　要

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.