Alkylpyridinium Hydrosulfate Ionic Liquids as Novel Additives for Zinc Electrodeposition

Abstract

The effects of three novel alkylpyridinium hydrosulfate ionic liquids (ILs)-EpyHSO4, BpyHSO4 and HpyHSO4 on current efficiency (CE), energy consumption (EC), catholic polarization behavior, surface morphology and crystallographic orientation during zinc electrodeposition from acidic sulphate solution were investigated. Addition of these additives was found to increase CE, decrease EC and improve the surface morphology at lower concentrations. Voltammetric studies indicated that these additives had a pronounced inhibiting effect on Zn2+ electroreduction and polarization of the electrode was in the order: HpyHSO4 > BpyHSO4 > EpyHSO4. X-ray diffraction analysis revealed that the presence of additives did not change the structure of the electrodeposited zinc but affected the crystallographic orientation of the crystal planes.