Inhibition of mild steel corrosion in hydrochloric acid by the seed husk extract of Jatropha curcas

The seed husk extract of Jatropha curcas has been studied for mild steel corrosion inhibition in acid medium. Traditional weight loss data obtained at four different temperatures are used to evaluate inhibition efficiency (IE) and thermodynamic parameters such as heat of adsorption of the inhibitor on the metal surface (Q), change in free energy of the reaction (AG), corrosion rate and energy of activation for corrosion reaction of mild steel (E). Temkinʹs adsorption isotherm was plotted to verify the nature of adsorption of the inhibitor on the metal surface. Infra red spectra were documented to fix the functional group responsible for inhibition. The electrochemical parameters are evaluated from the potentiodynamic Tafel polarization and impedance spectral studies. The surface morphology of the mild steel is analyzed using the SEM images. All the results obtained reflect that the seed husk extract of J. curcas as an effective eco-friendly and alternate corrosion inhibitor for mild steel in acid medium.