Cotrollable Preparation And Application Of Carbon-based And Titania-based Nanocomposites

Carbon-based nanocomposites have been become one of the hottest research field of materials science due to their excellent properties, such as solvent-resistance, big specific surface area, and good conductivity etc., and potential applications in electrophoretic display, Li-ion battery, catalyst, and biomedicine. In this thesis, though ultrasonic spray pyrolysis of aqueous solutions containing polycarboxylic compounds and metal salts, we developed a simple and low-cost method for obtaining several novel carbon-based nanocomposites, which resolved the existed questions reported in previous literature, such as high cost, eco-unfriendly, tedious process, long reaction time, and inapplicable for continuous production in a large scale, etc. Nanocomposites with different morphologies, such as core/shell, magnetic nanoparticles decorated in the shell of porous hollow carbon spheres, rattle-type hollow carbon spheres, etc., were produced via selecting different carbon source. Subsequently, we characterized and exploited aforementioned nanocomposites in some fields. The main results are outlined as follows:1. We have designed for the first time a general, template-free, one-step route to rattle-type hollow carbon spheres (M@carbon, M = Sn, Pt, Ag, or Fe-FeO nanoparticles). As an initial application, Sn@carbon has been successfully used as anode materials for Li-ion batteries, resolving the problem of pulverization and bad cycle performation of Sn-based anode materials.2. We have presented a rapid, template-free route to magnetic porous hollow carbon spheres, in which Fe3O4 nanoparticles randomly dispersed in the carbon shells. In comparison with previous literature, our magnetic porous hollow carbon spheres have the following advantages: higher loading of Fe3O4 (71 wt %), higher saturation magnetization (48.2 emu/g), better dispersibility in polar/nonpolar solvents, and better acid-resistance.3. To the needs of National Nature Science Foundation of China (No.60736001), we developed a doping-etching route to iron oxide-carbon black pigment with tunable density (1.5-2.2 g/cm3), which have been successfully exploited as black electrophoretic particles for electrophoretic display. Our black pigment resolved the problem of dismatched density between carbon-based black pigment and electrophoretic medium.4. Based on the mixed solvent method, using carbon as coupling agent, we further developed a general route to carbon/titania core/shell nanocomposites via replacing PS sphere template with carbon-based functional materials. The optical, magnetic, and catalytic properties of aforementioned nanocomposites were also investigated.