Anticorrosion Behavior of Persea macrantha Leaf Extract on Aluminium in Acidic Medium

Green corrosion inhibitors play an important role in mitigating the effects of toxic chemicals in the environment. In this point of view, in the present study, Persea macrantha (Kulamavu in Kerala) aqueous leaf extract was used as a potential corrosion inhibitor against the corrosion of aluminium metal in an acidic medium. Electrochemical and physicochemical methods were used to study its inhibitory effect. The impedance spectroscopic method reveals that the charge transfer process occurred during the inhibitory mechanism and indicates metal surface inhomogeneity. The potentiodynamic polarization study confirmed the mixed nature of the PM leaf extract. The corrosion rate of the substrate decreased significantly as inhibitor concentration increased. At an optimum concentration of 100 ppm, the PM leaf extract exhibited the highest inhibition efficiency of 98% in 0.2 N HCl. SEM investigation revealed the presence of a smooth surface of the adsorbed layer following the incorporation of the corrosion inhibitor.