Preparation And Properties Of Functional Nanocomposite Particles

With the development of nano-technology, nanocompsite particles which contain two or more nano-scale functional materials are an active study field of material. Magnetism core/shell nanocompsite particles are one of that. Hydrogen energy will surely take the place of fossil fuels as the new energy source in the future due to its advantages, such as high efficiency and low price. Hydrogen storage is the key problem in practical applications.In this article, Ni/MnO, Ni/TiO₂, Fe-MnO₂ and Fe-TiO₂ nanocompsite particles are prepared by the arc-discharge method using magnetism metals and oxides as the raw materials. Four nanocompsite particles are core/shell structure nanoparticles proved by XRD, TEM and FT-IR. The thermal analysis shows Ni/MnO and Fe-MnO₂ nanocompsite particles can improve the oxidation temperature of the core metals. The formation of nanoparticles was effectively explained by an extended mechanism of the Vapor-Liquid-Solid (VLS) with the existence of stoichiometric oxygen. The metal core plays an essential catalyst in the formation of the core/shell structure. The results of electromagnetism parameter analysis show that the different oxide shells have special effect to the electromagnetism parameter of the nanocompsite particles. Otherwise, the electromagnetism parameters of the nanocompsite particles decrease with increase of oxide shell.Mg-Cu alloy nanoparticles prepared by arc-discharge method are analyzed in this article. The results of XRD shows, the production is hardly affected by changing the proportion of the raw material. The formation rule of Mg-Cu alloy nanoparticles is illustrated according to thermodynamics. The Mg-Cu alloy nanoparticles have well hydrogen absorption properties after one time activation, during the test of hydrogen absorption capability of Mg-Cu alloy nanoparticles. The maximize of hydrogen absorption of Mg-Cu alloy nanoparticles is 2.05 wt%,1.97 wt% and 1.90 wt% at 623K,598K and 573K.