Synthesis of nickel hierarchical microstructures by a simple hydrothermal route

Abstract

Nickel hierarchical microstructures have been synthesized from the reduction of nickel hydrazine complexes by a simple hydrothermal method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and superconducting quantum interference device (SQUID). The results indicated that the Ni hierarchical microstructures are face-centered cubic phase with a size of 2–3 μ for a single hierarchical microstructure while some thick petals with a length in the range of 0.5–1.5 μ extrude around the surface. The value of coercivity reached 121 Oe at room temperature, which is vastly superior to that of bulk nickel. Parallel experiments showed that the hydrothermal reaction time and the presence of surfactant cetyltrimethylamonium bromide (CTAB) played important roles in the formation of such hierarchical morphology.