Electrochemical and quantum chemical studies on carbon steel corrosion protection in 1 M H2SO4 using new eco-friendly Schiff base metal complexes

摘要

Two new eco-friendly Schiff base metal complexes of Cr and Co were synthesized and characterized using UV and FTIR spectra. The complexes were evaluated as corrosion inhibitors against carbon steel dissolution in 1 M H2SO4 using electrochemical and quantum chemical studies. The electrochemical polarization and impedance measurements showed that their inhibition efficiencies are increased by increasing their concentration. The results state that the two complexes acted as mixed-type inhibitors. The degree of surface coverage values obtained from polarization and impedance techniques are in good agreement and all obeyed the Langmuir adsorption isotherm in its linear and logarithmic forms. The experimental inhibition efficiencies were correlated with their electronic properties via quantum chemical study. Additionally, the presence of a protective film on the carbon steel surface was confirmed using scanning electron microscopy (SEM). (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.