Pomegranate peel extract as a sustainable corrosion inhibitor on steel in a simulated concrete pore solution and mortar: Experimental and theoretical studies

Abstract

Various techniques, such as electrochemical impedance spectroscopy, potentiodynamic polarization, linear polarization resistance, and scanning electron microscopy, were used to investigate the inhibitory effect of pomegranate peel extract (PGPE) on the corrosion of carbon steel in a simulated concrete pore solution containing 0.5 M NaCl and in mortar exposed to chlorides. The results obtained revealed that the corrosion resistance of steel, in the presence of the PGPE, was greater than that of the inhibitor-free system, validating the ability of the pomegranate peel extract to produce a protective layer on the steel surface.The optimal concentration of pomegranate peel extract found is around 500 mg/L, with an inhibition efficiency estimated at 97.39%. It is worth indicating that the adsorption of PGPE was found to follow the Langmuir isotherm model. Furthermore, using the principles of quantum chemistry, the adsorption of PGPE constituents on the surface of carbon steel was shown to occur via donor-acceptor interactions.