Role of sodium decoration on the methane storage properties of BC3 nanosheet

Abstract

First-principles calculations including dispersion correction are carried out to investigate pristine and Na-decorated graphene-like BC3 (h-BC3) for their application as methane storage materials. Structural optimization shows that the methane is physisorbed on the pristine sheet via van der Waals forces with adsorption energy of −2.7 kcal/mol. It was found that unlike the pristine graphene, sodium decorated sheet can effectively interact with the CH4 molecule, so that each metal atom bound on sheet may adsorb up to four CH4. Furthermore, no bond dissociation was observed for the adsorption of CH4 on Na-decorated h-BC3, which means that decorated sheet can act as a storage device for methane safety storage. The results indicate that decoration of the Na atom on surface of sheet induces significant changes in electronic properties of the sheet and its E g is unchanged after adsorption of CH4 molecules. Theoretical methane storage capacity of Na-decorated BC3 nanosheet could approach 18.1 wt%.