Abstract

Inhibitive and adsorption properties of ethanol extract of Colocasia esculenta for the corrosion of mild steel in H₂SO₄ were investigated using weight loss, hydrogen evolution and IR methods of monitoring corrosion. The results obtained indicates that ethanol extract of C. esculenta is a good inhibitor for the corrosion of mild steel in H₂SO₄ and its inhibitive action is attributed to its phytochemical constituents which aided its adsorption on the surface of mild steel. Calculated values of activation energy and inhibition efficiency at 303 and 333 K revealed that the mechanism of adsorption of ethanol extract of C. esculenta on mild steel surface is physical adsorption. Also the adsorption of the inhibitor on mild steel surface was found to be spontaneous, endothermic and consistent with the assumptions of Langmuir adsorption isotherm.   

Key words: Corrosion, mild steel, inhibition, Colocasia esculenta.