Controllable synthesis of zinc-substituted α- and β-nickel hydroxide nanostructures and their collective intrinsic properties

A new controllable homogeneous precipitation approach has been developed to synthesize zinc-substituted nickel hydroxide nanostructures with different Zn contents from a zinc nanostructured reactant. As typical layered double hydroxides (LDHs), zincsubstituted nickel hydroxide nanostructures can be formulated as NiZn_x(Cl)_y(OH)_2(1+x)-y·z H₂O(x = 0.34-0.89, y = 0-0.24, z = 0-1.36). The structure and morphology of zinc-substituted nickel hydroxide nanostructures can be systematically controlled by adjustment of the zinc content. The effects of temperature and the amounts of ammonia and zinc nanostructured precursor on the reaction were systematically investigated. In our new method, although zinc-substituted α-and β-nickel hydroxides have the typical 3D flower-like architecture and stacks-of-pancakes nanostructures, respectively, their growth processes are different from those previously reported. A coordinative homogeneous precipitation mechanism is proposed to explain the formation process of zinc-substituted nickel hydroxide nanostructures. The zincsubstituted nickel hydroxide nanostructures exhibit some interesting intrinsic properties, and changing the zinc content can effectively tune their optical, magnetic, and electrical properties.