Abstract

Melilotus officinalis Extract (MOE), was investigated as a green corrosion inhibitor for aluminium in 1 M HCl solution using weight loss, hydrogen evolution, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Surface morphology was tested using scanning electron microscope (SEM). The effect of the temperature on corrosion behavior with addition of different concentrations was studied in the temperature range of 25-45 #xBA;C by weight loss method. Polarization curves reveal that the investigated extract is a mixed type inhibitor. The inhibition efficiency was found to increase with increase in the investigated extract concentration and increase with increase in solution temperature. The adsorption of the inhibitor on aluminium surface was found to obey the Temkin#x2018;s adsorption isotherm. The activation and adsorption parameters were calculated and discussed. The results obtained from chemical and electrochemical techniques are in good agreement.