Investigation of Withania Somnifera Extract as Corrosion Inhibitor for Copper in Nitric Acid Solutions

摘要

Corrosion inhibitive effect of Withania Somnifera extract has been studied in 0.5 M nitric acid forCopper (Cu). The studies were done at different temperatures (30-50 o C). The thermodynamicparameters were determined. Withania Somnifera has been found to be more effective corrosioninhibitor at lower temperatures and inhibition efficiency (IE) reached 91.8% at 25 ppm. Adsorptionisotherm was determined and was found to follow Frumkin adsorption isotherm. Inhibition efficienciesat different Withania Somnifera concentrations were determined using chemical and electrochemicaltechniques. Polarization data revealed that this extract acts as a mixed-kind inhibitor. The obtainedinhibition efficiencies were in a high agreement, confirming the validity of the used techniques intesting the inhibitory action of Withania Somnifera for Cu corrosion in nitric acid medium.