The stages of galvanostatic nucleation of zinc on the tungsten electrode from a zincate solution

Abstract

On the basis of the classical theory of galvanostatic nucleation and Vetter’s kinetic conception, formation of zinc nuclei on the tungsten electrode from the zincate electrolyte (0.5 М ZnO, 6 M NaOH) has been investigated. In the region of the current density 200 - 600 mАсm -2 the charge transfer overpotential (100 - 200 mV), the crystallization overpotential (50 - 60 mV), the nucleation work ((2 - 12)×10 -20 J), the number of atoms in the nuclei (2 - 10) were determined. It was proved that nucleation take place on reduced sites of the oxidized tungsten surface. Within the range of studied diapason of current densities nucleis are forming on energetically similar electrode centers. The low value of the charge transfer coefficient (α = 0.26) indicates a weak effect of the double layer electrical field on the activation energy of charge transfer.