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The effect of two alklpyridinium hydrosulfate based ionic liquids(ILs)including N-butylpyridinium hydrogen sulfate(BpyHSO4)and N-hexylpyridinium hydrogen sulfate(HpyHSO4)as additives on the nucleation and growth of copper from acidic sulfate bath was investigated using cyclic voltammetry,chronoamperometric and scanning electron microscopy techniques.Results from cyclic voltammetry indicated that the two studied additives had a blocking effect on copper electrodeposition process and this effect initiated by HpyHSO4was more pronounced in comparison to BpyHSO4.Dimensionless chronoamperometric current-time transients for the electrodeposition of copper from the bath free of additives were in good accord with the theoretical transients for the limiting case of instantaneous three-dimensional nucleation with diffusion-controlled growth of the nuclei.However,the instantaneous nucleation mechanism observed in the additive-free bath was changed to a more progressive one when additives were present in the bath.Surface morphology analysis indicated that alklpyridinium hydrosulfate ILs can induce the formation of leveled and finer grained deposits by the adsorption of additive at the first stages of deposition process,leading to decrease of the nucleation and growth rate of nuclei.
The effect of two alklpyridinium hydrosulfate based ionic liquids (ILs) including N-butylpyridinium hydrogen sulfate (BpyHSO4) and N-hexylpyridinium hydrogen sulfate (HpyHSO4) as additives on the nucleation and growth of copper from acidic sulfate bath was investigated using cyclic voltammetry, chronoamperometric and scanning electron microscopy techniques. Results from cyclic voltammetry indicated that the two studied additives had a blocking effect on copper electrodeposition process and this effect initiated by HpyHSO4was more pronounced in comparison to BpyHSO4.Dimensionless chronoamperometric current-time transients for the electrodeposition of copper from the bath free of additives were in good accord with the theoretical transients for the limiting case of instantaneous three-dimensional nucleation with diffusion-controlled growth of the nuclei. However, the instantaneous nucleation mechanism observed in the additive-free bath was changed to a more progressive one when additives were pres ent in the bath. Surface morphology analysis indicated that alklpyridinium hydrosulfate ILs can induce the formation of leveled and finer grained deposits by the adsorption of additive at the first stages of deposition process, leading to decrease of the nucleation and growth rate of nuclei.