Interaction of H, H2, and MgH2 With Graphene and Possible Application to Hydrogen Storage—A Density Functional Computational Investigation

The interaction of H, H₂, and MgH₂ with graphene is investigated using the density functional theory to explore the possibility of exploiting graphene or functionalized graphene as a hydrogen storage medium. The H atom is positioned at various distances from the graphene surface and the energetics are computed in detail. The extent of interaction of the s electron of H with graphene's p_z electrons is well brought out. Similar investigations are carried out for H₂, MgH₂. In the case of H atom, a HC covalent bond is formed. This process turns out to be a prerequisite for proton transfer through graphene. Interactions of H₂ and MgH₂ with graphene are different from that of H. It leads to the conclusion that functionalized graphene will better substrate/candidate for applications like hydrogen storage.