Study On Synthesis And Properties Of Carbon Nanotubes (CNTs)-Based Composites

Carbon nanotubes (CNTs) have attracted a great deal of attention in recent years because of their special structures, remarkable electrical and mechanical properties. Carbon nanotubes are used in various applications. The combinations of carbon nanotubes and other nanocrystals are expected to be useful in catalysts, sensors, nanoelectronic devices, data storage/ processing devices, field emission displays, and polymer or ceramic reinforcement. Therefore, deposition of some functional materials on carbon nanotubes has become an important field of study. The goal of the thesis is to explore the synthesis methods of novel MWNTs-based composites, to research on their optical,electronic,magnetic,catalytic properties and discuss the relation between the structure and properties of the composites. It establishes the foundation for developing the application of functionalized CNTs-based composites. The main work of this thesis included:1. EuF3 and TbF3 with the size about 10 nm were successfully coated on the multi-walled carbon nanotubes (MWNTs) by a simple and effective in-situ synthetic method without severely changing the energy states of the MWNTs for the first time. They were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results showed that the composite had optical properties. We also prepared MWNTs/PB composite using the same method, and it had electrochemical activity. This method offers experiences for synthesizing novel CNTs-based photoelectrical materials.2. Cu-Ag nanoparticles with atomic ratio of 2.1:1 and diameter of ca. 18 nm were decorated on acid-treated multi-walled carbon nanotubes by chemical reduction method, which was characterized by TEM, XRD, HRTEM and X-ray photoelectron spectroscopy (XPS). The MWNTs / Cu-Ag composite was used to construct a chemically modified electrode toward catalytic reduction of H2O2, the effect of catalysis is remarkable, which accumulates data for synthesizing novel electrochemistry sensors.3. The carboxyl functionalized carbon nanotubes MWNT-COOH were tried to catalyze the oxybromination of phenol and have high catalytic acitivities. The conversion of phenol and the selectivity of para- to...