摘要
钛酸四丁酯经酸性水解得到TiO2 溶胶 ,将溶胶与苯酚混合后加入到正庚烷分散介质中 ,再滴加甲醛水溶液 ,通过反相悬浮聚合和溶胶 凝胶过程制备了聚合物与TiO2 的复合微球 .对复合微球进行焙烧处理 ,使聚合物分解 ,从而得到由纳米TiO2 晶粒组成的多孔微球 .以示差扫描量热法、热重分析、X射线衍射、扫描电子显微镜和氮吸附等方法对TiO2 多孔微球的物理性质进行了表征 .结果表明 ,所得TiO2 多孔微球主要由锐钛型TiO2 纳米晶粒组成 ,晶粒尺寸为 2 0～ 30nm ;TiO2 多孔微球的直径为 2 0 0～ 5 0 0 μm ,比表面积为 87 4 0m2 /g ,平均孔径为 8 6 5nm ,孔径的分布具有单分散特征 .
The nanocrystalline titanium dioxide powder catalyst has many advantages in the waste water treatment. However, the powder catalyst is difficult to be recovered, which seriously limits its application. In this paper, the porous TiO2 microspheres were first prepared by the reversed-phase suspension polymerization and sol-gel method using reversed-phase suspension droplets as the templates. The TiO2 sol was prepared by hydrolysis of the tetrabutyl titanate precursor using anhydrous ethanol as the solvent and hydrochloric acid as the hydrolysis catalyst. The mixture of TiO2 sol and phenol was added into n-heptane and then the formaldehyde solution was added slowly. After reaction at 60 degreesC for 1.5 h, the TiO2-polymer microspheres were formed. Finally, the TiO2-polymer microspheres were calcined to remove the polymer and the porous TiO2 microspheres were obtained. The properties of the porous TiO2 microspheres were studied by differential scanning calorimetry, thermogravimetry, X-ray diffraction, scanning electron microscope, and N-2 adsorption. The results showed that the porous microspheres were mainly composed of anatase TiO2 nanocrystals whose size was between 20 nm and 30 nm. The diameter and surface area of the porous TiO2 microspheres were 200similar to500 mum and 87.40 m(2)/g, respectively. The pore distribution showed monodispersity and the mean pore size was 8.65 nm. Based on these structure characterization results, the porous TiO2 microsphere photocatalyst would be expected to have high photocatalytic activity and be able to be recovered with ease and therefore can be used repeatedly.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第4期301-304,共4页
基金
天津市自然科学基金资助项目 ( 0 0 36 4911) .
