Corrosion Inhibition of Aluminum in Acidic Solution by Aqueous Extract of Ajowan Plant as Green Inhibitor

Abstract

The inhibition of aluminum corrosion in 0.5 M hydrochloric acid by Ajowan plant was studied using chemical (weight loss) and ectrochemical (impedance and polarization) methods. The Ajowan plant extract was found to be good inhibitor for aluminum corrosion in 0.5 M hydrochloric acid in the studied concentration range of inhibitor. Corrosion inhibition could be explained by considering an interaction between metal surface and the inhibitor molecules. Electrochemical measurements showed that Ajowan inhibitor affects both cathodic and anodic Tafel slopes in HCl medium and act as mixed type inhibitor. The adsorption of Ajowan extract on the aluminum surface from HCl follows Langmuir adsorption model.