Electrodeposition of Ni-Cu alloys in an air and water stable room temperature ionic liquid

Due to the ligand property of the DCA anion, both CuCl and NiCl₂ are soluble in l-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) ionic liquid. Cyclic voltammograms of Ni(II), Cu(I), and Ni(II) + Cu(I), respectively, in EMIDCA were recorded on the glassy carbon electrode at 30°C. It is interesting to note that the thermodynamic deposition potentials of Ni and Cu are very close to each other. This is especially favorable for the electrodeposition of Ni-Cu alloys without any additive. The Ni-Cu alloys were electrodeposited using bulk controlled-potential electrolysis experiments. Energy-dispersive spectroscopy (EDS) data indicates that the composition of the Ni-Cu alloys not only depends on the deposition potential, but also on the Cu(I) and Ni(II) concentrations in the melt.