Anti-corrosive properties of quercetin and its derivatives on Fe(111) surface: a quantum chemical approach

Abstract

Quercetin, and its derivatives are potential anti-corrosive agents for mild steel in HCl as evaluated by recent weight-loss techniques as well as electrochemical studies. But the actual mechanism of anticorrosion and mode of adsorption of these inhibitors have not yet been explored. In the present work corrosion inhibition activity of quercetin, and its derivatives, are explored by density functional theory (DFT) in order to obtain inhibition efficiencies and reactive sites of corresponding compounds as possible corrosion inhibitors on Fe(111) surface. Quantum chemical parameters such as frontier molecular orbital (HOMO, LUMO) energies, charge distribution, electron affinity, ionization potential, dipole moment, hardness, softness, electronegativity, electrophilicity and charge transfer between quercetin and Fe(111) surface have been evaluated. Adsorption energies of quercetin derivatives on iron surface revealed that the binding is mostly chemisorptive in nature. There is close agreement between theoretical and experimental values of corrosion inhibition efficiency. Thus, suitably designed quercetin derivatives can act as good anti-corrosive agents on iron surface.