Inhibitive action of Chamomile extract on the corrosion of Iron: Density Functional Theory

Abstract

DFT calculations have been performed on major compounds of Chamomile extract as a green source of environmentally friendly corrosion inhibitors for Fe using B3LYP/6-31G^* level (d, p). Several global Quantum parameters were calculated on inhibitors and thermodynamic Gibbs function ∆G_ads of adsorption of Fe has been calculated and used to evaluate the inhibitive action of the each inhibitor. Quercetin has been found the highest anti-corrosion efficiency as compared to other compounds. Consequently, calculated global quantum parameters and thermodynamic function ∆G_ads show spontaneous physical adsorption of Apigenin-7-glucoside, luteolin-7-glucoside and  Quercetin  on Fe, wherase other inhibitors show non- spontaneous chemical adsorption.