Carbon-protected metallic nanoparticles(nickel and cobalt)composites were prepared by the pyrolysis of the mixture of soluble starch and metallic acetate in N2 flow via an easy green synthetic route.The obtained samples were highly stable in air.Reducing agent was not used in the experiments.The as-synthesized samples were characterized by XRD,TEM,and N2 adsorption-desorption analysis.The results of N2 adsorption-desorption analysis indicated that the obtained samples possessed mesoporous structures and high BET surface areas.
Porous metallic nickel has been synthesized using SiO2 opal as template. The template was prepared by self-assembled sedimentation of monodispersed SiO2 spheres. The metallic nickel precursor was impregnated into the void of the SiO2 opal template. The precursor transferred to metallic nickel after calcination in the nitro- gen atmosphere. Then, the SiO2 opal template was removed and three-dimensional porous metallic nickel with a meso-/macroporous structure was obtained. The as-synthesized samples were characterized by XRD, FESEM and nitrogen adsorption-desorption methods.
Ni（OH）2 with a high specific surface area was synthesized by a facile fast precipitation method.Porous nano-NiO was obtained by calcining Ni（OH）2 at 300 ℃.The NiO sample possesses a fine porous distribution at around 3-10 nm.The BET specific surface area and pore volume of this sample are 218.1 m2/g and 0.31 cm3/g,respectively.The electrochemical characteristics of the samples were studied by cyclic voltammetry and constant current charge/discharge.The specific capacitance of the NiO sample is about 255 F/g in the 2.0 mol/L KOH solution.The sample also has a fine electrochemical stability.
