Preparation And Characterization Of Nanomaterials Of Nickel, Nickel Oxide And Nickel Hydroxide

Based on detailed investigation of a great deal of related literature, the structure, property, application and synthetic method of nanomaterials have been reviewed. In this paper, on the basis of hydrothermal and solvothermal techniques, we developed several controllable synthetic techniques to fabricate urchin-like and wire-like nickel nanocrystalline, NiC₂O₄·2H₂O nanoboxes and nanofibres, NiO rods, flower-like β-Ni(0H)2 and flower-like NiO crystals. The crystallinities and morphologies of the products were characterized by XRD TEM, SEM, etc. The major contents can be summarized as follows:Metal nickel nanoparticles have been prepared by ultrasonic reduction in water. The prepared particles are spherical and their size is well-distributed. Urchin-like and wire-like nickel nanocrystallites have been synthesized by hydrazine reduction in ethylene glycol. The results reveal that solvent and reaction time play important roles in the morphology control of nickel nanocrytallites. The thus-prepared urchin-like nickel showed a much-enhanced coercivity than bulk nickel.NiC₂O₄ 2H₂O nanoboxes and nanofibres have been prepared by a solvothermal method in absolute ethanol. And we have synthesized wire-like nickel nanocrystals through the reduction of nickel oxalate nanofibres by hydrazine hydrate.NiO rods which consist of nanoparticles have been synthesized via thermal decomposition of rod-like nickel dimethylglyoximate precursor. The calcining time and temperature have less effect on the morphology of NiO rods. With increasing the calcining time and temperature, the size of particles became larger. The optical absorption band gap of the NiO nanoparticles was 3.51 eV.Flower-like /?-Ni(0H)2 crystals have been successfully prepared by a hydrothermal complexing-precipitation process at 140 °C for 4 h. Each flower is constructed with dozens of flakes, which are connected with each other. Ethylenediamine plays an important role on the flower-like morphology of the product. The influences of reaction temperature and surfactant (PVP) to β-Ni(OH)₂ morphology were also studied. Flower-like NiO nanocrystals have been synthesized by the thermal decomposition of Ni(OH)₂ precursor. Cyclic voltammogram(CV) shows flower-like NiO may be used as a good electrode material for supercapacitor.