Dysphania ambrosioides Essential Oil: An Eco-friendly Inhibitor for Mild Steel Corrosion in Hydrochloric and Sulfuric Acid Medium

Abstract

The medicinal plant products have been found to be active and eco-friendly anticorrosion agents. Corrosion inhibition of essential oil of Dysphania ambrosioides (DAEO) were investigated on mild steel C38 in 0.5 M H2SO4 and 1 M HCl solutions at different concentrations effect and different temperatures was evaluated using the weight-loss method and electrochemical measurements. The results indicated a maximum inhibition efficiency of 90% in 1 M HCl and 91% in 0.5 M H2SO4 which was reached using 4 g/L of DAEO at 298 K. The results obtained by electrochemical impedance spectroscopy show that the inhibitory action of this extract is based on the increase of the charge transfer resistance and the decrease of the double layer capacity. In addition, thermodynamic parameters, such as standard enthalpy of adsorption (ΔH°ads), standard free energy adsorption rate (ΔG°ads), and standard entropy of adsorption (ΔS°ads) were used to elucidate DAEO inhibitory action. In particular, density-functional theory (DFT) based methods, very suitable to study the electronic structure of mild steel and the main DAEO products. The quantum chemical parameters were measured and discussed.