Department of Chemistry, Gandhigram Rural University, Gandhigram, 624 302, Tamil Nadu, INDIA
Acid extract of Solanum tuberosum was tested as corrosion inhibitor for mild steel in 1 M HCl and H2SO4 media using different techniques: Weight loss (in different temperatures viz., 303, 313 and 323 K), Potentiodynamic polarization, Electrochemical Impedance Spectroscopy (EIS) and SEM techniques. The studies reveal that the plant extract act as good inhibitors in both the acid media and better in H2SO4 medium. Tafel polarization method indicated that the plant extract behaves as mixed mode inhibitor. Double layer capacitance and charge transfer resistance values derived from Nyquist plots obtained from AC impedance studies give supporting evidence for the anticorrosive effects of these plants. The inhibitive effect may be attributed to the adsorption of the inhibitor on the surface of MS following Temkin adsorption isotherm. Increase of inhibition efficiency with increase of temperature along with Ea values serve as proof for chemisorption. SEM studies provide the confirmatory evidence for the protection of MS by the green inhibitor. The study reveals the potential of the plantextract for combatingcorrosionwhich maybedue to the adsorption of alkaloids and other phytoconstituents.