Synthesis And Characterization Of Carbon Nanomaterials And Carbon Composites Materials

The point of this thesis is to explore new synthetic methods for micro-scale carbon materials. On the basis of comprehensive and thorough investigation of literatures concerning the developments of carbon nanotubes, carbon hollow nanospheres and carbon related composites' synthesis and application, in this dissertation, various controllable and novel methods including transition metal compound deoxidize method, catalytic decomposition method, and thermal-aqueous method were used to prepare the above mentioned materials, such as carbon nanotubes with different diameters, carbon hollow spheres, carbon spheres, olivary carbon particles, carbon rods, lanthanide hydroxides (Ln = Eu, La, Pr, Nd, Ce) nanorods with uniform diameters and lengths loaded on the surface of carbon nanotubes. Combining the experimental analysis results and the study of the related reports, the possible formation mechanism of the carbon materials was discussed. The main points are summarized as follow:1. Magnetic metal (Co and Ni) nanoparticles encapsulated in tips of carbon nanotubes have been successfully synthesized on a large scale using polyethylene glycol and metal oxalate at 450℃. Fe nanoparticles encapsulated in tips of carbon nanotubes prepared using ferrocene and sodium azide at 350℃. Systematic investigated the relation between the sizes of catalytic particles and the diameters of carbon nanotubes, the ferromagnetic properties and thermal stabilities of the products.2. On the basis of successful synthesis carbon nanotubes, lanthanide hydroxides rods loaded on the surface of carbon nanotubes were prepared. This synthesis process at 80℃, and this method was simple and facile. We can use this method synthesis other carbon materials. The photoluminescence of these composites display a strong red emission peak of Eu³⁺ at around 612 nm.3. Hollow carbon nanospheres with a yield of about 90% have been sunthesized through a facile approach using acetone and sodium azide as reactants at 400℃. Through tuning the experimental parameters, olivary carbon particles or carbon rods also have been selective prepared. The total surface area values evaluated from the analyzes of N₂ adsorption isotherm data. On the basis of the experimental results, a possible formation mechanism of the hollow carbon nanospheres was discussed.