Electrochemical and Thermodynamic Investigation of Drug Solfarlem as a Potential Corrosion Inhibitor for Nickel-Phosphorus Coatings

There are more materials being utilized as industry develops, and these materials are frequently exposed to severe corrosion while being employed. This depends on the material/corrosive pair and the environment in which these two elements come together; among the finest methods is the application of inhibitors to ensure their protection in contact with aggressive environments such as hydrochloric acid. This work describes the study of the corrosion behavior of a Nickel-Phosphorus coating in an acidic 1M HCl medium and the evaluation of the protective power of an organic compound. The Ni-P alloys were obtained by the electrodeposition technique from a solution containing Nickel Sulfate and Sodium Hypophosphite (NaH2PO2) on a steel substrate. The effect of drug Solfarlem as a corrosion inhibitor of Nickel-Phosphorus alloy in 1 M HCl was studied using electrochemical impedance spectroscopy, polarization curve and weight loss methods. Results show that the inhibition efficiency of this inhibitor by all methods was in good agreement and the optimal efficiency with a concentration of 6.10 – 5 mol/L was about 96%. The values for free energy of adsorption Gads, were calculated at each surface coverage, of the studied compound by applying the mathematical model. The adsorption of the inhibitor molecules corresponds to the Langmuir adsorption isotherm, followed by chemical adsorption on the surface of the Nickel-Phosphorus alloy.