Ceratonia siliqua extract as a green corrosion inhibitor for copper and brass in nitric acid solutions

摘要

The influence of extract of ceratonia siliqua extract on the corrosion of copper and brass in aqueous 1 M nitric acid was examined by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy and electrochemical frequency modulation techniques. The surface morphology was analyzed using scanning electron microscope and energy dispersive X-ray techniques. Potentiodynamic polarization curves indicated that the plant extract behaves as cathodic inhibitor. The results indicate that the extract solution of the plant could serve as an effective inhibitor for the corrosion of copper and brass in nitric acid media. As temperature increases, percentage of inhibition decreases. The degree of surface coverage of the adsorbed inhibitor was determined by weight-loss technique, and it was found that the results obeyed the Langmuir adsorption isotherm.