en گروه سطح پوشش و خوردگی Surface Coatings and Corrosion Research Paper Research Paper <p>Jatropha curcas leaves extract was tested as a green corrosion inhibitor for mild steel in aqueous hydrochloric acid solution using gravimetric and thermometric techniques. The results reveal that the inhibition efficiency vary with concentration of the leaf extract and the time of immersion. Maximum inhibition efficiency was found to be 95.92% in 2M HCl with 0.5 g/l concentration of the extract in gravimetric method, while 87.04% was obtained in thermometric method. The inhibiting effect was attributed to the presence of alkaloids, flavonoids, saponins, tannins and phenol in the extract. The adsorption processes of the Jatropha curcas leaves extract onto the mild steel is consistent with the assumptions of Langmuir isotherm model and also found to be spontaneous. From the results, a physical adsorption mechanism is proposed for the adsorption of Jatropha curcas leaves extract onto mild steel surface.</p> Mild steel, green inhibitor, corrosion, weight loss, thermometric, adsorption isotherms 1 11 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-877-1&slc_lang=en&sid=1 J. Odusote jamiukolawole@gmail.com 180031947532846004100 180031947532846004100 Yes University of Ilorin, Ilorin, Nigeria O. Ajayi ajayimichael2012@gmail.com 180031947532846004101 180031947532846004101 No University of Ilorin, Ilorin, Nigeria