Alocasia Odora Extract as Environmentally Benign Corrosion Inhibitor for Aluminum in HCl

The development of effective and environmentally benign corrosion inhibitors is now a major objective in the subject of corrosion. The impact of corrosion on aluminum in HCl has been investigated using leaves extract of Alocasia Odora (A. Odora) from Araceae family. Alocasia Odora is indigenous to Southeast Asia. The selected plant extract is nontoxic with LD50 > 0.5 g/kg (oral mice) and biodegradable. The leaf extract of Alocasia Odora was easily dissolved in HCl solution. The corrosion inhibition studies of plant extract were carried out using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopic (EIS). The A. Odora retards the rate of dissolution by 94% and exhibit excellent corrosion inhibition aluminum in HCl. The plant extract also shows potential inhibition (69%) at a longer immersion time (48h). The polarization curves showed that A. Odora acts as the cathodic inhibitor. A big capacitive loop present in the EIS at high frequencies, followed by a big inductive loop at low frequency values compared to blank, suggesting the effective corrosion inhibition in the presence of inhibitor. SEM results also depicted that the surface of aluminum with A. Odora extract smoother compared to blank.