Nucleation and growth orientation of zinc electrocrystallization in the presence of gelatin in Zn(ii)–NH3–NH4Cl–H2O electrolytes

Abstract

Nucleation and growth orientation of zinc electrodeposition in Zn(II)–NH₃–NH₄Cl–H₂O solutions were studied. XRD and SEM were used to characterize the structure and morphology of deposited-Zn films on cathodes. TEM and HRTEM were used to characterize the structure of zinc nuclei electrodeposited on a copper grid directly. Cyclic voltammetry was applied to investigate the nucleation process of zinc crystals. The growth orientation was assessed using Lotgering factor f according to the peaks of XRD patterns. The results showed that the addition of gelatin played a role in controlling the {110} orientation of the zinc crystal with maximum Lotgering factor f of 0.71 during zinc deposition. Change of overpotential, difference in stripping potential of different crystal orientation, controllable shape and size of zinc nuclei were observed with increase of the content of gelatin. The shape of the zinc nuclei was changed from fiber to particles when the content of gelatin was 75 mg L⁻¹ in solution.