First-principles study of Pt-film stability on doped graphene sheets

The stability of doped graphene sheets and a catalytic platinum (Pt) film on the doped sheets was investigated for a variety of dopants, using the first-principles calculations in the density functional theory. It was shown that the doping (dopant-substitution) energy increases as the differences of atomic radius and valency increase between the dopant atom and the host carbon atom. On the other hand, the adsorption energy of the Pt film becomes larger on doped graphene sheets, compared to that on undoped graphene sheet. We found a strong correlation between the adsorption and doping energies: the adsorption energy increases as the doping energy increases. This correlation occurs because the Pt-film adsorption partially releases hetero-valency-induced doping-energy loss through electron redistribution and atom-position change. We showed that cation-anion dopant pairs in the graphene sheet are also effective to stabilize adsorbed Pt films. (C) 2013 Elsevier B.V. All rights reserved.