Studies on the Inhibitive Effect of Datura Stramonium Extract on the Acid Corrosion of Mild Steel

The extract of Datura stramonium has been studied as a possible source of green inhibitor for corrosion of mild steel (MS) in HCl and H 2 SO 4 media at different temperatures. The anticorrosion effect was evaluated by conventional weight loss studies, electrochemical studies viz., Tafel polarization, ac impedance, and SEM studies. The studies reveal that the plant extract acts as a good inhibitor in both the acid media and better in H 2 SO 4 medium. Tafel polarization method indicate that the plant extract behaves as a 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 effect. 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 a proof for chemisorption. SEM studies provide the confirmatory evidence for the protection of MS by the green inhibitor. The study reveals the potential of D. stramonium for combating corrosion which may be due to the adsorption of alkaloids and other phytoconstituents.