Electrodeposition of Zn–Ta Coating from DMI–ZnCl2–TaCl5 Solvate Ionic Liquids

Abstract

In this work, the Zn–Ta coating was electrodeposited from DMI–ZnCl2–TaCl5 solvate ionic liquid. The electrochemical reaction was studied by cyclic voltammetry using titanium as working electrode. The onset potential of zinc and tantalum co-deposition was −0.7 V (vs. Ag). Moreover, potentiostatic electrodeposition experiments were conducted to investigate the influence of potential and temperature on the morphology of the coating. X-ray photoelectron spectroscopy analysis confirmed that the coating obtained by electrodeposition at −1.6 V (vs. Ag) and 353 K was composed of Zn, Ta, ZnO, and Ta2O5. The mass fraction of element tantalum was 6.21 %, and metallic tantalum accounted for 11.54 % of the mass of element tantalum. The corrosion current density of the Zn–Ta coating was 1.83 × 10−4 A cm−2.

Keywords

• ionic liquid
• tantalum
• zinc
• electrodeposition