First-principles study of Ni adatom adsorption on graphene for Ni-catalyzed carbonization of wood as electromagnetic shielding (EMS) materials

The functionalization and electric properties of graphene by the addition of transition metal atom of Ni to its surface had been investigated computationally using density functional theory with the generalized gradient approximation. The stable geometry adsorption position, binding energy, band gap, density of states, charge transfer of Ni adsorbed on graphene at two different coverages were calculated. The hollow site was the most stable adsorption site with the largest binding energy. The local density of states showed that carbon 2p orbital (pi bonded states) hybridized strongly with the 3d orbital of the Ni atom. Mulliken population showed the net charge (e) transferred from the Ni metal atom to the graphene was 0.87 of the (2x2) supercell and 1.05 of the (4x4) supercell respectively. All these changes of electric properties resulted in the band gap getting smaller and showing stranger conductivity after Ni adsorbed on the graphene.