Abstract: Flower-like Ni(OH)₂ microspheres were successfully synthesized with a facile template-free liquid process with hydrofluoric acid solution as the nickel ion ligand to form nickel-fluoro complex, NH₃ aqueous solution as the OH^- supplier and supplemental nickel ion ligand. The flower-like Ni(OH)₂ microspheres were composed of dozens of nanoflakes with α-Ni(OH)₂ and β-Ni(OH)₂ mixed crystallinity. Morphologies of the Ni(OH)₂ microspheres are influenced greatly by Ni(Ⅱ) concentrations while other solution conditions are fixed. When Ni(Ⅱ) concentration is 0.03 mol/L, the uniform flower-like Ni(OH)₂ microspheres with average diameters of about 2 μm were obtained and composed of nanoflakes with length of about 400 nm and thickness of about 60 nm. The formation mechanism from aggregation growth and surface growth to surface dissolution was proposed, which was in good agreement with observation on the Ni(OH)₂ samples during the reaction process.

Key words: Nickel hydroxide, Flower-like, Nanoflake