DIFFUSION-CONTROLLED REDUCTION OF Sb3+ AND Cu2+ TO METALS FROM IONIC LIQUIDS CONTAINING CHOLINE CHLORIDE

Sb3+/Sb and Cu2+/Cu couples were studied at 60 degrees C in ionic liquids containing choline chloride (ChCl) using cyclic voltammetry. ChCl-oxalic acid binary mixture was used as electrolyte and Pt and glassy carbon were the working electrodes. SbCl3 and CuCl2 as precursors were introduced into the ChCl-oxalic acid ionic liquid as solvent. Families of cyclic voltammograms were recorded for ionic concentrations of 5-16 mM Sb3+ and 8-20 mM Cu2+. The peak current square root of scan rate plots are straight lines passing through origin, thus demonstrating the diffusion control of cathodic processes. The diffusion coefficients of Sb3+ and Cu2+ ionic species were found to vary with the chemical nature of working electrode and of investigated electrolytes, partly reflecting the difference between complex species which may be present in ionic liquid.