Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization Analysis on Anticorrosive Activity of Thiophene-2-Carbaldehyde Derivative in Acid Medium

Abstract

The corrosion inhibition efficiency of thiophene-2-carbaldehyde tryptophan (T2CTRY) on mild steel (MS) in 1 M HCl solution has been investigated and compared using weight loss measurements, electrochemical impedance spectroscopy, and potentiodynamic polarization analysis. The Schiff base exhibited very good corrosion inhibition on mild steel in HCl medium and the inhibition efficiency increased with the increase in concentration of the inhibitor. The adsorption of the inhibitor on the surface of the corroding metal obeys Freundlich isotherm. Thermodynamic parameters (Kads, ΔG ads0) were calculated using adsorption isotherm. Polarization studies revealed that T2CTRY acts as a mixed type inhibitor. A maximum of 96.2% inhibition efficiency was achieved by EIS studies at a concentration of 1 mM.