The inhibition efficiencies of some organic corrosion inhibitors of iron: An insight from density functional theory study

Abstract

Molecular geometry, electronic structure, and adsorption behavior of a series of organic corrosion inhibitors have been studied by using a density functional theory (DFT) method. Among these organic corrosion inhibitors, 1H-benzotriazole is found to have the excellent corrosion inhibitor because of considerable adsorption energy. The electronic structure analysis shows that 1H-benzotriazole has the smallest HOMO-LUMO gap among all corrosion inhibitors studied here. Geometric optimization and electrostatic potential analysis show that three N atoms of triazole ring in 1H-benzotriazole are potential sites for adsorption on the Fe(111) surface. Mechanism investigation shows that the strong adsorption behavior arises from an donor-acceptor bonding interaction between Fe(111) surface and 1H-benzotriazole molecule.