Effects of 1-butyl-3-methylimidazolium hydrogen sulfate-[BMIM]HSO_4 on zinc electrodeposition from acidic sulfate electrolyte

摘要

A comparative study of the effect of 1-butyl-3methylimidazolium hydrogen sulfate-[BMIM]HSO_4 and gelatine on current efficiency (CE), power consumption (PC), deposit morphology, and polarization behaviour of the cathode during electrodeposition of zinc from acidic sulphate solutions were investigated. Compared with the traditional industrial additive, gelatine, the addition of [BMIM]HSO_4 was found to increase current efficiency, reduce power consumption, and improve the surface mor_phology. Maximum CE and minimum PC were obtained at the addition dosage of 5 mg dm~(-3). Meanwhile, simultaneous addition of the two additives induced a blocking effect of the zinc reduction and led to more leveled and fine-grained cathodic deposits. Moreover, cyclic voltammetry results and kinetic parameters such as Tafel slope, transfer coefficient, and exchange current density obtained from Tafel plots led to the conclusion that both additives have a pronounced inhibiting effect on Zn~(2+) electrore_duction. The data obtained from X-ray diffractogram revealed that the presence of additives did not change the structure of the electrodeposited zinc but affected the crystallographic orientation of the crystal planes.