Effects of 1-butyl-3-methylimidazolium hydrogen sulfate-[BMIM]HSO4 on zinc electrodeposition from acidic sulfate electrolyte

Abstract

A comparative study of the effect of 1-butyl-3-methylimidazolium 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 morphology. 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? electroreduction. 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.

Ionic Liquids as Electrodeposition Additives and Corrosion Inhibitors

“…In addition, enormous organic additives [53][54][55][56][57][58][59][60][61][62] 4 , which relects increasing absorbability at the electrode surface with increasing molecular size and hence molecular mass [62,63] 4 , which shows the adsorbability of the studied additives and relects their efect on the process of deposition. The analysis of the kinetic parameters [18,19] indicates that the presence of ILs does not have any signiicant efect on the Tafel slopes and transfer coeicients, suggesting that they do not change the zinc electrodeposition mechanism in the absence of additives. (4) [OMIM]HSO 4 [18,19].…”

“…The analysis of the kinetic parameters [18,19] indicates that the presence of ILs does not have any signiicant efect on the Tafel slopes and transfer coeicients, suggesting that they do not change the zinc electrodeposition mechanism in the absence of additives. (4) [OMIM]HSO 4 [18,19].…”

“…The zinc deposit obtained from addition-free electrolyte is bright but not smooth and consists of hexagonal platelets of moderate size (Figure 2a). Introducing the additives into the solution did not afect the shape of the crystals but improved the quality of deposits by reducing the platelet sizes and giving smooth and compact deposits (Figure 2b and d) with changing the preferred crystal orientations [18,19].…”

“…In contrast, 24-h long-term successive electrolysis and high-temperature treatments have no efect on the activity of [BMIM]HSO 4 [67]. [18,19].…”

“…Some of the most important prosperities of ILs are their thermal stability and avirulence, which make them potential additives for metal electrodeposition and green inhibitors for metal anti-corrosion. In our previous studies, alkylimidazolium, alkylpyridinium and quaternary ammonium-based ionic liquids were observed to be an excellent levelling agent in zinc [18][19][20][21][22] and copper [23][24][25] electrodeposition and showed favourable corrosion resistant on metals such as aluminium [26], copper [27] and mild steel [2].…”