Hydrogen storage properties of Li-, Sc-, Ti-decorated Ψ-graphene: A DFT study

Abstract

In this paper, the hydrogen storage performance of Sc (Ti, Li)-modified [Formula: see text]-graphene ([Formula: see text]-g) is investigated by density functional theory (DFT). Sc and Ti can be stably adsorbed on [Formula: see text]-g with the binding energies of 4.78 eV and 4.83 eV, respectively. Li atoms can also be stably absorbed on B-doped [Formula: see text]-g with the binding energy of 2.51 eV. In addition, Sc and Ti atoms attached on [Formula: see text]-g can adsorb up to ten and eight hydrogen molecules, and the hydrogen gravimetric storage capacity reaches 7.93 wt.% and 6.20 wt.%, respectively. Li atoms attached on B-doped [Formula: see text]-g can adsorb up to eight hydrogen molecules with the hydrogen gravimetric storage capacity 9.32 wt.%, all meeting DOE standards. On the whole, Bader charge analysis shows that the charge is transferred from C atoms to H atoms, which is more conducive to hydrogen adsorption. All the researches prove that the Sc, Ti-decorated [Formula: see text]-g and Li-decorated B-doped [Formula: see text]-g are potential hydrogen storage materials.