Importance of anions in electrodeposition of nickel from gluconate solutions

Abstract

Electrodeposition of nickel from slightly acidic gluconate solutions containing chloride or/and sulfate ions was investigated. Electrochemical measurements correlated with bath speciations showed nickel chloride complex and nickel sulfate complexes as crucial species affecting cathodic reactions in a potential range up to −1.3V. At more negative potentials, nickel deposition was governed by a release of nickel cation from nickel-gluconate complex. This was further evidenced by differences in nucleation modes, morphology, and structure of the deposits. Wettability of as-plated and chemically modified nickel layers were determined and correlated with their morphology and corrosion resistance.

Effect of Chloride and Sulfate Ions on Electrodeposition and Surface Properties of Alloys Produced from Zinc-Nickel-Manganese Gluconate Baths

“…free cations in the first range and NiGlu + complex at more electronegative potentials, similarly to phenomena observed formerly in the nickel baths. 20 It should be emphasized that nickel/zinc ratios in the deposits were always smaller than in the baths, regardless on the codeposition conditions. This is typical for an anomalous codeposition of these two metals.…”

“…Particular fractions were calculated using stability constants of the individual species summarized in the earlier papers. [19][20][21][22][23] The assessment did not include boric acid and its complexes with the metal ions, since the acid exists in a molecular form at given pH, while the data on complexation reactions are tentative or uncertain. 27,28 However, it should be emphasized that a possible liability of the calculations can be caused by boric acid dissociating in the near-cathode solution layer that can turn more alkaline during high current electrolysis and thus leading to form various polyborate species as potential complexing ligands.…”

“…Successful codeposition of binary Zn-Ni and Zn-Mn alloys as well as pure metals from various gluconate baths were reported in the previous papers. [19][20][21][22][23] Speciation of gluconate electrolytes containing chloride, sulfate or mixed metal salts has been shown to have a greater effect on morphology, wettability and corrosion properties for pure zinc than for pure nickel or binary alloys. On the other hand, the solution composition affected kinetics and mechanism of the electroreduction of the metal ions.…”

Structural Control of Electrodeposited Sb Anodes through Solution Additives and Their Influence on Electrochemical Performance in Na-Ion Batteries

“…A brightener can inhibit the rate of the electrodeposition by interacting with the electrode surface and preventing the deposition of the active ion in that area . As a result, brighteners can also help level the micro profile of the electrode surface without the need for polishing after the deposition. , Additives, such as bis­(3-sulfopropyl) disulfide (SPS) that acts a brightner, − and sodium gluconate, , are typically used in copper and nickel plating baths, respectively, and an extensive library of additives have been investigated for other metal depositions. ,, Surfactants, such as cetyltrimethylammonium bromide (CTAB), have also been used in deposition baths due to their potential to affect the surface tension between the electrolyte and the electrode and can have effects on coating adhesiveness and morphology at varying concentrations. , Depending on the interactions of CTAB with the substrate or the active metal being deposited, it may act as a leveling or brightening agent. − Additonally, CTAB can interact directly with the deposited metal instead of the substrate and has been used to cap the growth of particles as demonstrated in nanoparticle synthesis − and also has the potential to act as a corrosion inhibitor . Despite the tunability that can be acheived through these organic additives, there are few publications reporting the tunability of electrodeposited Sb anodes for battery applications using solution additives. , …”

“…37 As a result, brighteners can also help level the micro profile of the electrode surface without the need for polishing after the deposition. 27,37 Additives, such as bis(3-sulfopropyl) disulfide (SPS) that acts a brightner, 38−40 and sodium gluconate, 41,42 are typically used in copper and nickel plating baths, respectively, and an extensive library of additives have been investigated for other metal depositions. 36,43,44 Surfactants, such as cetyltrimethylammonium bromide (CTAB), have also been used in deposition baths due to their potential to affect the surface tension between the electrolyte and the electrode and can have effects on coating adhesiveness and morphology at varying concentrations.…”