TiO_2超细粒子的微乳法制备、表征及性能研究

采用表面活性剂OP-7、正庚烷、水和异戊醇形成的微乳体系制备TiO2超细粒子,并考察水和异戊醇含量对TiO2超细粒子平均粒径的影响。所得产物易于分离,溶剂可回收,产率达80%。结果表明,500℃灼烧2h所制备的TiO2超细粒子为锐钛型。采用FTIR、XRD、BET、DSC、TEM对TiO2超细粒子进行表征,由FTIR分析可知,表面无残留有机物;由DSC分析可得晶型转变温度为437 3℃;根据XRD分析计算的平均粒径为9 7nm,颗粒分散度较高;采用BET法测定比表面积为85 8m2/g。以苯酚的光催化氧化作为目标反应来评价TiO2超细粒子的光催化活性。苯酚光催化降解反应2 5h,降解率可达85%。

Characterization and Photocatalytic Performance of TiO2 Ultrafine Particles Prepared with Microemulsion Method

Ultrafine TiO_2 particles were prepared by hydrolysis of tetrabutyl titanate in the nanodroplets of water/OP-7/iso-pentanol/ heptane microemulsions.The effects of the contents of water and iso-pentanol on the average grain size of TiO_2 were investigated.The as-prepared particles could be separated simply and the solvents were reclaimed in the process of preparation.The yield reaches 80%.Properties of TiO_2 ultrafine particles were charactered by DSC,FTIR,XRD,BET and TEM.The results showed that the as-prepared particles were amorphous and transformed into the anatase phase at 437.3 ℃.Annealed at 500 ℃ for 2 h,no organic materials on the surface of the particles were found by FTIR analysis.Their average grain size is 9.7 nm and BET specific surface is 85.8 m~2/g.The photocatalytic performance of this ultrafine TiO_2 particles was investigated in the photocatalytic process using phenol as a model reactant.Illuminated for 2.5 h with the TiO_2,degradation ratio of phenol is 85%.