Potentiostatic Nucleation of Zinc on a Pyrolitic Carbon Electrode from a Zincate Electrolyte Containing Polymeric Tetraalkylammonium Salt as an Additive

Abstract

Potentiostatic formation of zinc nuclei on an isotropic pyrolitic carbon electrode from a zincate solution with no additive and an electrolyte containing polymeric tetraalkilammonium salt (TAS) was studied. The process was analyzed taking into account an influence of hydrophobic and hydrophilic parts (zones A and B, respectively) of the electrode surface on the charge transfer and crystallization stages. Due to specific features of TAS adsorption on the surface of zones A and B, nucleation results in formation of two groups of nuclei. A little number of nuclei (N~10^5 cm-2) is formed on those parts of zones B which are "free" from the additive. On sites of zones A and B "occupied" by TAS, nucleation occurs at a high supersaturation and a large number of nuclei (N~10^8 cm-2) is formed. The number of nuclei in the both electrolytes is controlled by nucleation exclusion zones.