水热法制备过程中TiO_2纳米纤维成形机理研究  

Forming Mechanism of TiO_2 Nanofibres Prepared by Hydrothermal Method

作　　者：周艺[1] 游洋[2] 张世英[3] 万隆[2] 许第发[3] 匡加才[1] 

机构地区：[1]长沙理工大学化学与环境工程学院,长沙410076 [2]湖南大学材料科学与工程学院,长沙410082 [3]长沙学院生物工程与环境科学系,长沙410003

出　　处：《无机材料学报》2008年第5期1075-1079,共5页Journal of Inorganic Materials

基　　金：湖南省自然科学基金(06JJ4068);湖南省教育厅优秀青年基金(058001)

摘　　要：采用水热法制备出φ20～30nm,长度达微米级的TiO_2纳米纤维,以XRD、TEM、IR等手段对不同工艺条件下获得的产物品型结构、微观形貌以及化学组成进行了表征,对TiO_2纳米纤维成形机理进行探讨,并就洗涤过程中pH值对纤维结构的影响进行分析.结果表明,TiO_2纳米纤维的形成机理可能是锐钛矿型TiO_2纳米颗粒在强碱作用下生成K_2Ti_6O_(13)颗粒,小颗粒沿一定晶轴生长,遵循溶解-生长机理,逐渐长成纳米纤维.清洗溶液的pH值对产物的成分和结构有较大影响,通过控制清洗溶液的pH值和热处理温度,可以获得组成分别为K_2Ti_6O_(13)、H_2Ti_3O_7和TiO_2的纳米纤维.在pH=7、80℃烘干条件下得到的主要是H_2Ti_3O_7纳米纤维,400℃煅烧后转变为TiO_2纳米纤维.The TiO2 nanofibres with the diameter of Ф20-30nm and the length of micron-dimension were successfully synthesized by hydrothermal method. Their crystalline structure, morphology and chemical composition were characterized by the transmission electron microscope （TEM）, X-ray diffraction patterns （XRD）, infrared spectrum （IR）, etc. The forming mechanism of the TiO2 nanofibres and the effects of pH value in the process of washing on the nanofibres structure were investigated and analyzed, respectively. The results indicate that the forming mechanism of the TiO2 nanofibres can be described as following： K2Ti6O13 nanoparticles are initially formed in alkaline solution using anatase nanoparticles as raw materials, and then gradually grown to nanofibres along a certain crystalline axis obeyed the dissolution-growth mechanism. The pH value of washing solution has a significant influence on the structure and composition of the products. The nanofibres of K2Ti6O13, H2Ti3O7 and TiO2 can be obtained by the controlling of the pH value of washing solutions and heat-treatment temperature. The products, washed in solution with pH=7 and dried at 80℃, form the nanofibres of H2Ti3OT, which is subsequently calcined to form TiO2 nanofibres at 400℃.

关 键 词：水热法 TIO2 机理 纳米纤维 

分 类 号：O643[理学—物理化学]