Abstract
In this study, anticorrosive properties of various extracts (methanolic, aqueous methanolic and water extracts) of Anthemis pseudocotula for mild steel in 1.0 M HCl media is screened for the first time. Among the various tested extracts, the methanolic extract of A. pseudocotula shows the highest corrosion inhibition activity. Anticorrosive assay-guided isolation of this methanolic extract results in the isolation of a highly potent anticorrosive compound, APB (luteolin-7-O-beta-D-glucoside). The anticorrosive effects of APB on mild steel in 1.0 M HCl media were evaluated in detail using gravimetric, Tafel plots, linear polarization, electrochemical impedance spectroscopy and SEM and EDS techniques. Tafel plots reveal that APB acts as a mixed-type inhibitor. The adsorption behaviour of this green inhibitor on the mild-steel surface obeys the Langmuir adsorption isotherm. A surface morphology study through SEM and EDS analysis displays a noteworthy upgraded surface morphology of the mild steel plate in the presence of the green inhibitor in 1.0 M HCl media. The results obtained from electrochemical tests and weight loss measurements are in good agreement which shows excellent inhibition efficiency for the natural compound APB.