Electrochemical and Quantum Chemical Calculations of Two SchiffBases as Inhibitor for Mild Steel Corrosion inHydrochloric Acid Solution

The corrosion inhibition characteristics of two synthesized Schiff bases, namely N, N´-bis(2-hydroxy-6-nitrobenzaldehyde) benzidineand N, N´-bis(salysylaldehyde) benzidine, on the mild steel corrosion in 2.0 M hydrochloric acid have been investigated by weightloss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques. These studies were carried out atdifferent concentrations, temperatures and durations. Polarization measurements indicate that the two inhibitors act as mixed typeinhibitors. The adsorption of inhibitors obeys the Langmuir adsorption isotherm and the thermodynamic parameters (Ea, Kads, ΔG0ads)were calculated and discussed. Quantum chemical calculations were performed to provide further insight into the inhibitionefficiencies determined experimentally.