Effect of sodium benzoate on zinc electrodeposition in chloride solution

Abstract

The effect of sodium benzoate on the electrodeposition of zinc on carbon steel electrode from acidic chloride solution was studied by cyclic voltammetry (CV), differential capacitance (DC), chronoamperometry (CA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). A dimensionless graph model was used to analyze the nucleation process of zinc. It is found that the sodium benzoate has a blocking effect on the zinc electrodeposition when its concentration is higher than 0.03 M but will accelerate the formation rate of zinc nuclei when its concentration is lower than 0.03 M. Benzoate can be adsorbed on the surface of the electrode, which reduces the interface tension of electrode/solution and favors the formation and growth of zinc nuclei when its concentration is lower than 0.03 M, but forms a separated layer and retards the formation and growth of zinc nuclei when its concentration is higher than 0.03 M.