Synthesis Of Zero-dimensional Carbon Materials And Study On Their Adsorption Capability

As its unique spherical structure and special properties in electrinics, magnetics, mechanics, chemistry and so on, zero-dimensional carbon materials has been a new star in high-tech materials field. It attracts many worldwide scientists to focus on it. Theory calculation and practical study indicate that zero-dimensional carbon materials has huge potential application value. In recent years, the articles about zero-dimensional carbon materials in the international science journal increase greatly, indicating that the study on zero-dimensional carbon materials is in the ascendant. So far, study on the preparation and properties of zero-dimensional carbon materials have been carried out widely in abroad and at home, but the study on its adsorption capability and application is rather less.In this paper, ideal parameter for preparation of carbon microspheres was probed by chemical vapor deposition (CVD), using acetylene, toluene and mixture of them as carbon source. Individual nano onion-like fullerenes and Fe nanoparticles encapsulating nano onion-like fullerenes (nano-Fe@OLFs) were synthesized by DC arc-discharge in water and CVD. The microstructures of zero-dimensional carbon materials by different methods were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The results revealed that without catalyst, a great deal of carbon microspheres with high purity and uniform diameter could be prepared from the mixture of acetylene and toluene at 1000°C; After microwave treatment and high temperature vacuum treatment, on the carbon microspheres prepared with this parameter, the graphite degree was enhanced greatly. Especially after high temperature vacuum treatment clear graphite stripe appeared inner; Great deal of individual nano onion-like fullerenes and Fe nanoparticles encapsulating nano onion-like fullerenes (nano-Fe@OLFs) were synthesized by DC arc-discharge in water and CVD; After nitic acid oxidation on different zero-dimensional carbon materials no function corps were introduced to the surface of them. Different oxidation time was performed on them.Nitrogen adsorption isotherms for all the samples studied are measured at 77K on Sorptomatic 1990 automatic physics and chemistry instrument. The results show that adsorption isotherms of carbon microspheres are complex. Both after high temperature vacuum and microwave treatment the pore volume decreased, and the specific surface area increased. After high temperature vacuum treatment the adsorption capability decreased but after microwave treatment it increased; Two fullerenes had similar complex adsorption isotherm. The adsorption property of this two was different, and the adsorption capability of individual nano onion-like fullerenes was lower; As its big size and solid structure, the adsorption capability of carbon microspheres was far lower than that of fullerenes; After nitric acid oxidation, the adsorption Isotherms of all the samples translated to III type; Only after 15h oxidation the adsorption amount raised, but that of fullerenes dropped consistently; The specific surface area of carbon microspheres increased after 6h, 12h and 15h oxidation, but that of fullerenes increased only after 12h oxidation.