Stability of gold atoms and dimers adsorbed on graphene

We report density functional theory (DFT) calculations for gold atoms and dimers on the surface of graphene. The calculations were performed using the plane wave pseudopotential method. Calculations were performed for a variety of geometries, and both the graphene surface

and gold atoms were allowed to fully relax. In agreement with experiment, our results show that the gold–gold interaction is considerably stronger than the gold–graphene interaction, implying that uniform coverage could not be attained. The minimum energy configuration for a single gold atom is found to be directly above a carbon atom, while for the dimer it is perpendicular to the surface and directly above a carbon–carbon bond. Our results are consistent with previous similar calculations.