Interaction of Hydroxyl OH Radical with Graphene Surface: A Density Functional Theory Study

Abstract

The interaction of a hydroxyl OH radical with a graphene surface has been investigated by the density functional theory (DFT) method in order to elucidate the radical scavenge mechanism of the graphene surface. The DFT calculation showed that the OH radical binds directly to the carbon atom of the graphene surface and a strong C–O bond is formed. The binding energies were dependent on the cluster size and were distributed in the 4.1–9.5 kcal/mol range at the B3LYP/6-31G(d) level of theory. The potential energy curve plotted as a function of the distance of OH from the surface carbon showed that the OH radical can bind to the carbon atom with a low activation barrier: the barrier heights for n = 7 and 14 were calculated to be 3.9 and 1.9 kcal/mol, respectively. Also, it was found that the structural change from sp2 to sp3-like hybridization occurs by the approach of the OH radical.