Oxygen reactivity on pure and B-doped graphene over crystalline Cu(111). Effects of the dopant and of the metal support

Molecular oxygen reactivity on pristine and B-doped graphene over crystalline Cu(111) surface has been investigated by means of density functional theory (DFT) calculations and the periodic supercell approach. Results obtained for the supported undoped and doped systems have been compared to establish the effect of B-doping on the reactivity and on the interface adhesion, which are found to be both highly boosted. Additionally, results obtained for free standing pristine and B-doped graphene have been compared to those obtained for the metal supported counterparts in order to determine how the reactivity is affected by the presence of the metal substrate. Cu is found to be an n-type donor which enhances the reactivity of pristine graphene. However, in the case of B-doped graphene, the n-type doping by the metal surpasses the p-type doping by boron causing a reduction in the reactivity. Finally, the possibility that the oxygen could dissociate at the graphene/metal interface is investigated. Some of the reaction products are found to be more stable than those obtained with oxygen dissociating on the top side of the graphene sheet. This provides some significant insight into the confinement effect on the surface chemistry of molecules underneath which is currently a hot topic in the field.