Cathodic process of nickel electrodeposition from ammonia–ammonium chloride solutions
| Autor: | Zhi-Ying Ding, Ya-Ning He, Shijun Liu, Liang Yuan |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
inorganic chemicals
Materials science Inorganic chemistry chemistry.chemical_element 02 engineering and technology Electrolyte 010402 general chemistry 01 natural sciences Chloride Redox Ammonia chemistry.chemical_compound parasitic diseases Materials Chemistry medicine Physical and Theoretical Chemistry Tafel equation Reaction step Metals and Alloys 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Nickel chemistry Linear sweep voltammetry 0210 nano-technology medicine.drug |
| Zdroj: | Rare Metals. 42:1061-1066 |
| ISSN: | 1867-7185 1001-0521 |
| DOI: | 10.1007/s12598-017-0975-9 |
| Popis: | Mechanism of cathodic process on nickel electrodeposition from ammonia–ammonium chloride solutions was studied by Tafel polarization curves, linear sweep voltammetry (LSV), cyclic voltammograms (CV) and chronopotentiometry (CE) technologies. In the electrolyte with 1.0 mol·L−1 NiCl2·6H2O, 4.0 mol·L−1 NH3·H2O and 2.5 mol·L−1 NH4Cl, nickel ion mainly complexed with ammonia and almost no free nickel ion could be found. It is confirmed that the dominant form of nickel ammonia complex ion in the system is Ni(NH3) 4 2+ by measuring the equilibrium potential of the electrode at various concentrations of ammonia. The species of Ni(NH3) 4 2+ turns into Ni(NH3) 2 2+ during pre-chemical reaction step before discharging reduction reaction. Then, Ni(NH3) 2 2+ discharges at the cathodic interface to form metal nickel deposit directly. Nucleation process is involved during nickel electrodeposition according to CV results. The reduction reaction of Ni(NH3) 2 2+ is irreversible which is controlled by diffusion step. Other processes are also accompanied during the electrodeposition process, except for the diffusion-controlled process. |
| Databáze: | OpenAIRE |
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