| Abstract: | Shell/core-type MnO-coated Ni nanoparticles was prepared by arc discharge method using micron-sized Ni and MnO2 powders as the raw materials, and the evaporating atmosphere was a mixture of hydrogen and argon. The morphology, structure and chemical composition of the as-prepared nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermal gravity analysis (TGA), respectively. It was showed that most of nanoparticles were in spherical shape in the range of 30-60 nm, with a shell of MnO phase and a core of Ni. The formation of nanoparticals was effectively explained by an extended mechanism of the Vapor-Liquid-Solid (VLS) with the existence of stoichiometric oxygen. The Ni core plays an essential catalyst in the formation of the core/shell structure. |
