Zinc electrodeposition from a chloride-free non-aqueous solution based on ethylene glycol and acetate salts

In this work, the electrodeposition of zinc is carried out from a chlorides-free organic solution based on ethylene glycol (EG) and acetate precursor salts. The formation of an EG-complex with zinc was observed through H-1 NMR. The electrochemical characterization was performed by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) on platinum and steel respectively. Electrodeposition was investigated with both potentiostatic (from -1 V vs Pt to -2 V vs Pt) and galvanostatic (from -2 mA/cm(2) to -16 mA/cm(2)) approaches together with Hull cell test: cathodic efficiencies > 85% were reported. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses showed that the films were compact, with large grains and a hexagonal microstructure preferentially oriented along the [002]/[102] directions. The high purity of the deposits was assessed by electron dispersive spectroscopy (EDS). Polarization tests in de-aerated 5 %wt NaCl solution resulted in a corrosion potential of E-corr = -1.03 V vs Ag/AgCl (I-corr = 1.01 x 10(-6) A/cm(2)). (C) 2018 Elsevier Ltd. All rights reserved.