Azadirachta Indica Extract as corrosion Inhibitor for Copper in Nitric Acid Medium

Azadirachta Indica (AI) leaves extract was investigated as a copper corrosion inhibitor in nitric acid. Corrosion rate and inhibition properties were studied by using weight-loss, effect of temperature, polarization and electrochemical impedance spectroscopic methods. Corrosion rate increases with the increase in acid concentration and temperature. The percentage of inhibition efficiency (I.E.) increases with increase AI concentration. The value of free energy of adsorption (∆Ga) and heat of adsorption (Qads) obtained were negative. The inhibition effect is discussed in view of AI molecules adsorbed on the metal surface and it follows Langmuir adsorption isotherm. Polarization curve indicates that inhibitor act as mixed type (anodic and cathodic) and the inhibition efficiency was found up to 98%. It was found that AI extract is good inhibitor for the corrosion of copper in nitric acid medium.