Influence of Additives and Pulse Electrodeposition Parameters on Production of Nanocrystalline Zinc from Zinc Chloride Electrolytes

Abstract

Pulse electrodeposition was used to produce nanocrystalline zinc from an aqueous zinc chloride electrolyte with polyacrylamide and thiourea as additives. The influence of additive concentration and pulse electrodeposition parameters, namely, current-on time, current-off time, and peak current density on the grain size, surface morphology, and preferred orientation was investigated. The grain size and surface morphology of zinc deposits were studied by scanning electron microscopy and field emission scanning electron microscopy. The preferred orientation of zinc deposits was studied by X-ray diffraction. The optimum concentrations of polyacrylamide and thiourea in the bath that give the finest grains were 0.7 and 0.05 g/L, respectively. At constant current-off time and peak current density, the grain size decreased asymptotically with increasing current-on time. An increase in the current-off time at constant current-on time and peak current density resulted in grain growth. A progressive decrease of the grain size was observed with increasing peak current density at constant current-on and -off time. Nanocrystalline zinc with an average grain size of 50 nm was obtained at a peak current density of 1000 mA/cm 2 . The crystal orientations developed were correlated to the variation in the cathode overpotential accompanied with changing the electrodeposition parameters. A (101 ¯3) preferred orientation was developed at low overpotential while higher overpotential developed a dual (112 ¯2) (101 ¯0) orientation.

Optical properties of pulse electrodeposited ZnS films

“…The trend of decreasing grain size with increasing current on-time can best be explained by an increased number of nucleation sites caused by the higher overpotential at longer current on-times. The same behavior of increasing overpotential with current ontime was also found during zinc deposition from a chloride-based electrolyte [17]. Moreover, at low duty cycles, the OFF time is more compared to ON time, hence, the deposited species have sufficient time to nucleate and grow thus increasing the thickness.…”

Effect of reaction parameters in synthesis, characterisation of electrodeposited zinc nanohexagons

“…Zinc can be electrodeposited from acid or alkaline [23], cyanide, non-cyanide [22], and bromide, sulphate [21], or chloride [24,25] type of electrolyte. The sulphate type baths are used for the high-speed deposition and chloride baths are used for higher throwing power.…”

Template‐Free Electrodeposition of Zinc Nanowires from an Ionic Liquid

“…[1][2][3] Furthermore, they are used, for example, in zinc/airb atteries. [4][5][6] Zinc can be depositedf rom aqueous electrolytes [7][8][9][10] with low current efficiencies, owing to hydrogen evolution.…”

“…The template-free synthesis of zinc nanowires was achieved from Zn(TfO) 2 in 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate ([Py 1,4 ]TfO) at 125 8C. The electrodeposition process was evaluated by using cyclic voltammetry.T he electrodeposited zinc was characterizedb yu sing scanning electron microscopy (SEM) and X-ray diffraction.…”