Electrochemical investigation of Irbesartan drug molecules as an inhibitor of mild steel corrosion in 1 M HCl and 0.5 M H2SO4 solutions

Abstract

Inhibition effects of Irbesartan drug on mild steel corrosion in 1M HCl and 0.5M H2SO4 solutions have been investigated by open circuit potential (OCP) curves, Tafel polarization curves, linear polarization curves and electrochemical impedance spectroscopy (EIS) along with cyclic voltammetry (CV), UV–visible, FTIR and NMR spectroscopy techniques. Maximum corrosion inhibition of 94% and 83% have been achieved at 300mgL−1 Irbesartan concentration in 1M HCl and 0.5M H2SO4, respectively. Adsorption of Irbesartan on mild steel surface is studied by SEM and various isotherm models, which follows Langmuir isotherm. The effects of rise in temperature and acid concentration on the corrosion behavior of mild steel in both acid solutions are also studied by weight loss method. Corrosion inhibition by Irbesartan is explained on the basis of experimental results as well as frontier molecular orbitals estimated by CV and UV–visible spectroscopic measurements.