Phase and particle of Y-doped Ni(OH)₂ prepared from different nickel sources and Na₂CO₃ amount

Multiple nano-sized α-Ni(OH)₂ was synthesized by ultrasonic-assisted precipitation under different conditions. The crystal structure and particle size distribution of the sample were characterized with X-ray diffraction (XRD), infrared spectroscopy, and laser particle size analyzer (PSA). The results show that the samples are anisotropic polycrystalline of α and β Ni(OH)₂, and the ratio of α and β changes with the difference of nickel source, resulting in the largest ratio of α-Ni(OH)₂ using nickel nitrate as reactant. Larger amount of Na₂CO₃ is conducive to the formation of α-Ni(OH)₂; while the resultant phases are all β with the same conditions but no doping. The results of PSD indicate that the samples are about 100–120 nm in size, and the sample with nickel sulfate as nickel source has the minimum particle size. The three ions of nickel source appear in the absorption peaks in the Fourier transform infrared spectrum showing that the ions change the crystal structure of Ni(OH)₂. EDS testing shows that Y and anion distribute in the lattice of α-Ni(OH)₂ uniformly.