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.

Acidic Ionic Liquids

“…The cell based on electrolyte containing 20 wt % poly-AIL yielded an overall energy conversion efficiency of 6.95% under AM 1.5 illumination at 100 mW cm –2 . A number of acidic ionic liquids have been used as neat liquids as well as additives in electrodeposition experiments, which include: [C 4 C 1 im]­[HSO 4 ], , [C 2 py]­[HSO 4 ], [C 4 py]­[HSO 4 ] and [C 6 py]­[HSO 4 ] in the electrodeposition of zinc, [(C 2 ) 4 N]­[HSO 4 ], [(C 4 ) 4 N]­[HSO 4 ], [C 4 py]­[HSO 4 ] and [C 6 py]­[HSO 4 ] in copper electrodeposition, , [(C 1 ) 3 HN]­[Cl], [(C 2 ) 3 HN]­[Cl] in the electrodeposition of Al, [C 2 C 1 im]­[AlCl 4 ] in the electrodeposition of Al–W alloy − and octyl-3-methylimidazolium chlorogalate in the electrodeposition of Ga …”

Electrodeposition in Ionic Liquids

“…for grain refining. [17][18][19][20] However, this application of ILs in aqueous baths is beyond the scope of this article. There is not much literature to be found on the effect of additives in deposition from ILs.…”