Dibenzyl disulfide adsorption on Cu(111) surface: a DFT study

Abstract

The adsorption of dibenzyl disulfide (DBDS) on a Cu(111) surface model was investigated by using density functional calculations, considering energetic and electronic aspects. Several complexes were generated, where the bridge, hollow hcp, hollow fcc and top adsorption sites were considered. The results show that the Cu–S interaction guides the final complexes, and a secondary π–Cu weak interaction confers an extra stability. The complexes were grouped as physi- or chemisorption according to their adsorption energy applying a distortion decomposition model, with a preference by a double interaction of S with Cu (i.e., hollow hcp and bridge sites). A degree of disulfide bond dissociation was observed in the complexes, being correlated with adsorption energies. From an electronic aspect, it was found that the electronic flow from copper to DBDS occurs in the most stable complexes, checked with charge analysis. These results are in agreement with experimental revelations of copper corrosion on power transformers.