制备均一形貌的长二氧化钛纳米管

Preparation of Long TiO_2 Nanotubes with Uniform Morphology

在温和的水热条件下 ,用碱溶液处理不同粒径的锐钛矿相和金红石相二氧化钛纳米粉体 ,得到了不同形貌的二氧化钛纳米管 ,并用TEM ,XRD ,FT Raman和BET等对其进行了表征 .金红石相的超细纳米晶有利于形成均一形貌的纳米管 ,用粒径仅为 7.2nm的金红石相纳米粉体为前驱体得到了长度为 5 0 0nm的长二氧化钛纳米管 .用纳米晶反应活性对晶粒尺寸的依赖性及晶相稳定性解释了长纳米管的形成机理 .

TiO 2 nanotubes with different morphology were prepared by treatment of TiO 2 nanocrystals in mild hydrothermal conditions in alkaline solution. TiO 2 nanotubes were characterized by TEM, XRD, FT Raman and BET specific surface area techniques. The effects of particle size and crystalline phase of TiO 2 nanoparticles on the morphology of the resulting nanotubes were investigated. TEM and BJH pore size distributions show that the ultrafine rutile typed nanoparticles in size of 7.2 nm can form much longer nanotubes than those derived from rutile in larger size or in the anatase phase. The formation mechanism of long TiO 2 nanotubes was interpreted in the light of the relative stability of crystalline phase and the dependence of reactivity on the particle size under mild hydrothermal condition in the alkaline solution.