Effect of alkyl group position on adsorption behavior and corrosion inhibition of new naphthol based on 8-hydroxyquinoline: Electrochemical, surface, quantum calculations and dynamic simulations

Abstract

The present investigation focused on the corrosion inhibition of mild steel in 1.0 M HCl medium by new naphthol based on 8-hydroxyquinoline. These products were characterized by 1H-NMRand 13C NMR spectroscopy. The influence of concentration (C) and temperature (T) on the corrosion process of mild steel before and after addition of naphthol derivatives in corrosive solutions has been investigated through weight loss (WL), electrochemical measurements :electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). PDP findings revealed that the used naphthol derivatives exhibit a mixed character. Inhibition efficiencies of Q-1 and Q-2 followed the order: 87.6% (Q-1) < 90.9% (Q-2). The study has shown that these inhibitors act through adsorption mechanism onto steel surface following Langmuir isotherm. The surface analyzes were carried out by SEM, EDS, AFM, and XRD. The corrosive solutions were analyzed by UV–visible and ICP-OES. Experimental and spectroscopic studies were confirmed using DFT calculations and MD simulations.