Al doped graphene: A promising material for hydrogen storage at room temperature

Abstract

A promising material for hydrogen storage at room temperature–Al doped graphene is proposed theoretically by using density functional theory calculation. Hydrogen storage capacity of 5.13 wt % is predicted at T=300 K and P=0.1 GPa with an adsorption energy Eb=−0.260 eV/H2. This is close to the target specified by U.S. Department of Energy with a storage capacity of 6 wt % and a binding energy of −0.2 to −0.4 eV/H2 at ambient temperature and modest pressure for commercial applications. It is believed that the doped Al alters the electronic structures of both C and H2. The bands of H2 overlapping with those of Al and C simultaneously are the underlying mechanism of hydrogen storage capacity enhancement.