Journal of Applied Electrochemistry, Vol.38, No.9, 1203-1210, 2008
Voltammetric and morphological characterization of zinc electrodeposition from acid electrolytes containing boric-polyalcohol complexes
The influence of sorbitol or glycerol polyalcohols on the electrodeposition of zinc and on morphology of the zinc film is discussed. The deposition current efficiency, in the potential range -1.30 V to -2.50 V, was similar to 90% in all baths. Increasing the sorbitol concentration in the bath shifted the deposition to more negative potentials, similar to 50 mV, and decreased the current density (j(p) ) of the zinc deposition significantly. On the other hand, adding glycerol did not significantly affect either j or the deposition potential of zinc. Scanning electron microscopy (SEM) showed that either sorbitol or glycerol lead to the formation of granular deposits. The best zinc morphology was obtained with 0.52 M sorbitol or glycerol in the plating bath. The presence of sorbitol or glycerol in the plating bath was beneficial, since the resulting zinc deposits were compact and without holes.