Hydrogen storage in Al and Ti dispersed on graphene with boron substitution: First-principles calculations

Abstract

The characteristics of hydrogen adsorption on Al and Ti metal atoms dispersed on graphene with boron substitution is investigated including metal adatom clustering and electronic structure of H-2/metal-adsorbed graphene using density functional theory calculations. It is found that Al and Ti atoms are well dispersed on boron-substituted graphene and can form a (2 x 2) pattern because clustering of metal atoms is hindered by the repulsive Coulomb interaction between metal adatoms and strong bonding force between dispersed metal atom and boron-substituted graphene. In addition, Al and Ti can bind up to eight H-2 molecules on the double side of the boron-substituted graphene. This allows for a storage capacity of a 9.9 wt% and 7.9 wt% hydrogen for Al and Ti adatom, respectively.