Density functional theory study of imidazole, benzimidazole and 2-mercaptobenzimidazole adsorption onto clean Cu(1 1 1) surface

Density functional theory was used to investigate the adsorption of three corrosion inhibitors on the Cu(1 1 1) surface in both neutral and dehydrogenated forms, including imidazole, benzimidazole and 2-mercaptobenzimidazole. Results show that three neutral molecules can weakly chemisorb perpendicularly on the surface through NCu or SCu bond as well as the X H⋯Metal hydrogen bond (X = C or S). Neutral benzimidazole and 2-mercaptobenzimidazole can physisorb almost parallel to the surface. The dehydrogenated molecules can strongly chemisorb on the surface with both perpendicular and tilt adsorption configurations, and their chemisorption strength order is consistent with the experimental results of inhibiting efficiency.

► The interaction of three corrosion inhibitors with Cu surface was studied.
► Density functional theory and periodic slabs approach were used.
► We studied inhibitor molecules in both neutral and deprotonated forms.
► The deformation charge density and projected density of states were analysed.