Electric field improved hydrogen storage of Ca-decorated monolayer MoS2

Abstract Hydrogen storage property of Ca-decorated MoS 2 is carried out using first-principles calculations. Our calculations demonstrate that the preferential binding of Ca atoms on MoS 2 effectively prevent the Ca clustering. Six H 2 molecules per Ca atom can be adsorbed with a desirable adsorption energy of 0.14 eV/H 2 . Both hybridization of the Ca-3d and S-2s with the H-1s orbital and the polarization of the H 2 molecules contribute to the hydrogen adsorption. Our results show that the external electric field can effectively tune the hydrogen adsorption energy, therefore making hydrogen storage and release reversible.