Abstract :
Based on density-functional theory, we find that B-doped graphene significantly enhances the Be adsorption energy and prevent Be atoms from clustering. The complex of Be adsorbed on B-doped graphene can serve as a high-capacity hydrogen storage medium: the hydrogen storage capacity (HSC) can reach up to 15.1 wt% with average adsorption energy −0.298 eV/H2 for double-sided adsorption. It has exceeded the target specified by US Department of Energy with HSC of 9 wt% and a binding energy of −0.2 to −0.6 eV/H2 at near-ambient conditions. By analyzing the projected electronic density of states of the adsorbed system, we show that the high HSC is due to the change of electron distribution of H2 molecules and a graphene system decorated with B and Be atoms.
