Influences of Saccharin on Electrochemical Behavior of Nickel Electrodeposition

Abstract

Electrodeposition of Ni was performed in acid Watt's solutions. Saccharin concentrations were varied in order to analyze its influence on the electrochemical behaviors of Ni deposition. Investigations were conducted using CHI660D, by methods of linear potential sweep, cyclic voltammetry and A. C. Impedance. Results indicate that with the increase of saccharin concentration, the cathodic polarization, apparent activation energy and the electrochemical reaction resistance of Ni electrodeposition increase. The exchange current density decreases with the increase of saccharin concentration. The electrodeposition of Ni is a mixing process controlled by electrochemical polarization and concentration polarization. The change of saccharin concentration does not affect the electrodeposition mechanism of Ni. But there is an obvious inhibition and blocking effect of saccharin on nickel electrodeposition. When the concentration of saccharin is 4g/L, its adsorption capacity in electrode is close to saturation. The saccharin concentration should be less than 4g/L.