AFM Studies of the Effect of Chloride Ion on the Morphology of the Copper Electroplating Surface

Delgosha, Masoud; Salehi, Samira; borujeni, Leila Unesi; Sharifi, Soheil

doi:10.11648/j.optics.20140302.12

Cited by 3 publications

(1 citation statement)

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“…Because chloride ions have a higher polarizability than other anions, they can even enhance the deposition of most metals. The polarizability of chloride ions (8.9 cm 3 /mol) is greater than that of sulphate ions (3.9 cm 3 /mol); thus, whereas the exchange current density for Zn deposition in a sulphate solution is ~ 3.10 − 5 A/cm 2 , it is an order of magnitude higher in chloride solutions [37] [38] [39]. The effect of chloride ions on the current e ciency and morphology of Zn deposit during electrolysis is still subject to several uncertainties.…”

Section: Introductionmentioning

confidence: 99%

Interpreting the main effects on the efficiency and morphology for establishing a procedure of electrodepositing Zn from purified chloride SPL solutions

Zakiyya,

Illés,

Kékesi

2024

Preprint

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Detailed potentiodynamic and galvanostatic methods have been used to investigate the electrodeposition of Zn and to develop a reliable recovery method from a purified and concentrated spent pickling liquor (SPL) of hot dip galvanization. Applying various combinations of Zn concentration, pH, agitation, apparent current density (c.d.) and additional NaCl concentration, a uniform initial deposit could be observed at the cathode, however the subsequent dendrite formation and the development of protrusion at the edges were targeted for a deeper investigation. The potentiodynamic experiments, showed the importance of H2 evolution influenced by the electrolyte properties and the cathodic polarization. The cathodic current was dominated by Zn reduction in the pH > 2 range during the fast potentiodynamic runs of the 30 – 150 g/dm3 Zn concentration range in the stationary electrolyte. Increasing the Zn concentration could considerably improve the deposit morphology. In the long-term galvanostatic experiments the current efficiency increased with the increase of pH in the examined wide Zn concentration range but the c.d. needs optimization. A current efficiency (c.e.) of ~99% can be reached with an electrolyte of pH ~5, Zn concentration ~50 g/dm3 applying a c.d. in the 300 – 600 A/m2 range. At low (~10 g/dm3) Zn concentrations the rate of hydrogen evolution increases dramatically. The addition of NaCl can practically improve the c.e. if the Zn concentration is at least around 50 g/dm3. In contrast, this improvement is largely off-set by the negative effects of strong H2 evolution at as low Zn concentrations as e.g. 10 g/dm3. Higher NaCl additions or too high Cl- ion concentrations, however inhibit the cathodic reaction of the electroactive species by stronger chloro-complex formation. In this case the intensive H+ reduction causes hydroxide precipitation.

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Section: Introductionmentioning

confidence: 99%