Berry Leaves Extract as Green Effective Corrosion Inhibitor for Cu in Nitric Acid Solutions

Abstract

The corrosion of Cu in 2 M HNO₃ in the presence of berry leaf extract (BLE) has been studied utilizing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), electrochemical frequency modulation (EFM), and weight loss techniques. Polarization studies demonstrated that this extract acts as a mixed-type inhibitor. The inhibition efficiency (IE) of this extract has been found to vary with the concentration of the extract and the temperature and reached 90.1% at 300 ppm and 45°C. The adsorption of this extract on the surface of Cu from the corrosive environment has been found to obey the Temkin adsorption isotherm. The thermodynamic parameters of Cu corrosion in 2 M HNO₃ were calculated and discussed. The surface morphology of the Cu surface was examined using different techniques. The Fouriertransform infrared spectroscopy (FTIR) results showed that the inhibition mechanism was via the absorption process, through the functional groups present in the extract molecules.