Electroanalytical, quantum and surface characterization studies on imidazole derivatives as corrosion inhibitors for aluminum in acidic media

In this study, the effect of imidazole derivatives on the inhibition of aluminum corrosion in 0.5 M HCl has been studied using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) measurements. The results show that all imidazole derivatives are good inhibitors, and inhibition efficiency follows the order: B > A. Polarization curves demonstrated that the imidazole derivatives were of mixed-type inhibitors. The adsorption of each inhibitor on aluminum surface obeys Frumkin adsorption isotherm. Surface morphology studies were done using scanning electron microscopy (SEM) to characterize the film formed on aluminum surface. Quantum chemical calculations show that imidazole derivatives can adsorb on the aluminum surface through the nitrogen atoms as well as π-electrons in the imidazole ring.