Authors: J.W. Chung, H.-J. Kim and S.-Y. Kwak
Affilation: Seoul National University, Korea
Pages: 301 - 304
Keywords: cyclodextrin, mesoporous titanium dioxide, sol-gel process, hydrothermal treatment
Mesoporous titanium dioxide (CD-TiO2) sphere with pore diameter in several nanometers and narrow pore size distribution was prepared from beta-cyclodextrin (beta-CD) and titanium precursor via sol-gel reaction in aqueous acidic condition. beta-CD was used as template to generate the nano-sized pore, and retarding agent was utilized to control the high reactivity of titanium precursor. After sol-gel reaction, hydrothermal treatment was performed to CD-TiO2 for acquirement of anatase-type crystalline with excellent photocatalytic activity. From BET and BJH results, it was found that the pore with diameter in several nanometers (ca. 3~4 nm) and narrow size distribution was formed to the CD-TiO2. TEM and FE-SEM images clearly showed that sphere-type TiO2 particle with non-ordered wormhole-type pore structure was constructed to CD-TiO2. WAXD result showed that CD-TiO2 had the crystalline structure of anatase-type due to the hydrothermal treatment. No thermal decomposition of beta-CD in CD-TiO2 were observed in TGA curves. These WAXD and TGA results can be explained by the fact that -CD was removed of itself during sol-gel process and washing treatment, because the pore size of CD-TiO2 increased over size of beta-CD (ca. 1.5~2 nm) by the growth of TiO2 crystalline attributed to the polymerization between Ti precursors.