Inhibition of Galvanostatic Nucleation of Zinc from a Zincate Solution by Cations of the Polymeric Tetraalkylammonium Salt

Abstract

Galvanostatic formation of zinc nuclei on an isotropic pyrolitic carbon electrode from a pure zincate solution and a solution containing an additive of the polymeric tetraalkilammonium salt (TAS) was studied. The process was analyzed taking into account hydrophobic and hydrophilic parts (zones A and B, respectively) of an electrode surface on the charge transfer and crystallization stages. Due to a specific behavior of TAS adsorption on the surface of zones A and B, the nucleation process occurs in two steps. During the first period a few number of nuclei (N~105 cm-2) are formed on sites of zones B which are not occupied by TAS molecules. Under conditions of the constant j and inhibition of nuclei growth it causes an increase of supersaturation and secondary nucleation on occupied by TAS sites of the electrode and formation of a large number of nuclei (N~108 cm-2).