Study on Synthetic Methods of Mesoporous Carbons for Various Potential Applications

• Main Authors: Chia-hsien Chang, 張家憲
• Other Authors: Hong-ping Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/08502428872896035065

碩士 === 國立成功大學 === 化學系碩博士班 === 96 === Porous carbons with high surface area, large porosity and good electric conductivity are of great interest for its extensive applications, such as adsorbents, solid templates, catalytic supports or raw materials of electric conduction and electric capacity. In this study we present novel synthetic methods based on the mesoporous carbons to fabricate other metal and metal oxide@mesoporous carbons, mesoporous metal oxides for various potential applications. First, we used the mesoporous carbons as solid template, by impregnating various metal precursors into the mesopores of the carbon. The metal ions or metal alkoxides was adsorbed and confined in the nanochannels of the mesoporous carbons. Then, a high-temperature calcination at 600–700oC was used to remove the carbon templates and enhance the crystallization degree. Therefore, the mesoporous metal oxides with high surface area, large pore volume and high crystalline have been efficiently prepared. Secondly, the mesoporous carbons was impregnated with the Fe(NO3)3, Ni(NO3)2 or Co(NO3)2 salt, and then treated under different two atmosphere: (1) heated at 1000 oC under N2 to increase the graphite extent of carbons; (2) heated at 700oC under C2H2/H2 environment for chemical vapor deposition of carbon nanotubes anchored on the mesoporous carbon spheres. These two treatment procedures can enhance the electric conduction of the mesoporous carbons to extend the applications of the electric conduction and electric capacity. In addition to the thermal treatments aforementioned, we used a fast and high-efficiency method to generate the metal or metal oxides@carbons by using microwave radiation as heating source. The Fe, Co or Ni precursors containing mesoporous carbon were subsequently exposed to an microwave oven for 5–10 min. The mesoporous carbon materials containing magnetic nanoparticles were quickly synthesized. Extending this method, we can also obtain the anatase-TiO2/Carbon composites from a fast microwave radiation of the TiO2 precursor@mesoporous carbon. To incorporate the nitrogen into the TiO2 framework, the mixture of carbons, TiO2 precursor and urea was directly exposed to microwave radiation, and then calcined at 600–700oC. The light yellow N-doped TiO2 powders which could absorb visible light were easily produced.