Density functional theory study on the interaction of magnesium ions with graphene surface

Abstract

The interactions of magnesium species (Mg, Mg+, and Mg2+) with a graphene surface have been investigated by the density functional theory (DFT) method. The distances of Mg atoms from the graphene surface were calculated to be 1.80 Å (Mg2+), 2.16 Å (Mg+), and 4.17 Å (Mg) at the Coulomb-attenuating method (CAM)-B3LYP/6-31G(d) level. The binding nature of Mg ions (Mg2+ and Mg+) is caused by the charge transfer interaction, and the Mg atom interacts with the surface via van der Waals (vdW) force. The Mg ions can diffuse via the C–C bond center between hexagonal sites. The barrier heights for the diffusion of Mg2+ and Mg+ on the graphene surface were calculated to be 14.6 and 2.8 kcal/mol, respectively. On the other hand, the diffusion of Mg atoms proceeds with a very low barrier. The mechanism of the interaction of Mg with the graphene surface was discussed on the basis of theoretical results.