Understanding the inhibition performance of novel dibenzimidazole derivatives on Fe (110) surface: DFT and MD simulation insights

In order to delay or solve the issue of metal material corrosion, six benimidazole derivativesmolecules namely, 2,6- bis (benzimidazole-2′-yl) pyridine (A), 2,5- bis (benzimidazole -2′-yl) pyridine (B), 2,4- bis (benzimidazole -2′-yl) pyridine (C), 2,3- bis (benzimidazole -2′-yl) pyridine (D), 3,5- bis (benzimidazole-2′-yl) pyridine (E), 3,4- bis (benzimidazole -2′-yl) pyridine (F), have been designed and used as corrosion inhibitors. The adsorption behavior and inhibition mechanism of six inhibitors on the Fe (110) surface had been investigated by the molecular dynamics (MD) simulation and quantum chemical calculation. MD simulations revealed parallel orientation of the above six molecules on the iron surface. In quantum chemical calculations, the energy of the highest occupied molecular orbital ( E HOMO ), energy of the lowest unoccupied molecular orbital ( E LUMO ), energy gap (Δ E = E LUMO - E HOMO ), electronegativity (χ), chemical hardness (σ), and softness (η) were applied for their possible interaction modes with the surfaces. It was found that F molecule among the six novel corrosion inhibitors has strong adsorption capacity, good environmental stability, and potential applications in corrosion protection of iron surface.