Study of electrochemical redox of gold for refining in non-aqueous electrolyte

The electrorefining of gold by simple electrolysis was investigated in the ionic liquid, 1-ethyl-3-methyl-imidazolium bis (trifluoromethanesulfonyl)imide (EMIMTFSI) with titanium tetrachloride (TiCl4) used as a supporting electrolyte at room temperature. From the cyclic voltammetry results, optimal electrorefining conditions were found for selective dissolution of gold from an anode and for selective reduction on a cathode under potentiostatic conditions, in which is able to obtain pure gold on a cathode surface. The composition, crystal structure, and morphology of pure gold were confirmed by X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. The electrodeposited gold was uniformly distributed on the platinum electrode surface without any impurities by non-aqueous electrolysis at room temperature.