Synthesis And Applications Of Carbon Encapsulated Copper Nickel Alloy Nanoparticles

Carbon encapsulated metal nanoparticles (CEMNPs) are new carbon materials. They have the representative core/shell structure, in which graphite layers arrange around the center (filled with nano-metal). Because of their special structures and unique physical and chemical properties, they might be used as electro-catalysts, battery materials, the electro-magnetic waves shield materials and friction materials.For the preparation of CEMNPs, the present techniques show some disadvantages, e.g., the morphology and the structure of the resulting nanoparticles are not easy to control, costly and it is difficult to produce high-purity nanoparticles in large quantities. Carbon encapsulated copper nickel alloy nanoparticles(CECNANPs) with core/shell structure were successfully prepared in nitrogen atmosphere by mixing, evaporation, carbonization, annealing, concentrated nitric acid total immersed, ultrasound purified methods under the simple and mild conditions, in which sucrose functioned as carbon precursor, copper nitrate hydrate and nickel nitrate used for source of the metal nanoparticles. The elements, morphology and structure of the product were characterized via EDS, XRD, HRTEM. The results indicated the shape of product was quasi-spherical, a single particle distributed uniformly with the size about 20-30nm, the core of the as-prepared was fcc-CuNi, rather than that of carbide phases or oxide phases. TG-DTA-DTG measurements suggested that the carbon shell increased antioxygenic property of the copper nickel alloy nanoparticles.The CECNANPs was used as the additive of paraffin, and its tribological properties were investigated by XP tester with various additive amounts, different loads and rotate speeds. The results indicated 0.6wt.% was the best adding concentration and its friction coefficient was slightly lower than that of paraffin, but raised the anti-wear property greatly,the flatness and smoothness of tribological surface was enhanced. The CECNANPs was used as the additive of alkyd resin, the adding concentration of CECNANPs on the viscosity of coating, the adhesive force and the hardness of paint film were inspected, the results concluded 15wt.% was the best adding concentration. The CECNANPs was used as the working electrode to discuss the electro-catalytic activity for PNP and methanol with various scan velocity. The results suggested PNP had good electro-catalytic reduction activity, its process was mainly controlled by diffusion. But it did not show electro-catalytic activity for methanol under the same conditions.