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 1H 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/cm2 to −16 mA/cm2) 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 Ecorr = −1.03 V vs Ag/AgCl (Icorr = 1.01 × 10−6 A/cm2).