水热法制备纳米TiO_2纤维及光催化降解亚甲基蓝的研究

PREPARATION AND CHARACTERIZATION OF TITANIA NANOFIBRES

采用水热法,以锐钛矿型TiO2粉体为前驱体,与10mol/L的KOH溶液反应,成功地制备出了TiO2纳米纤维。通过XRD,HRTEM,BET和FT-IR等手段对纳米纤维的微观形貌、晶型结构及化学组成进行表征。结果表明:80℃烘干条件下所得产物为三钛酸H2Ti3O7纳米纤维,纤维的长径比达到了50以上,且生长很均匀,热处理温度为550℃时完全转变为锐钛矿。在FT-IR图中,煅烧后的纤维的吸收峰的强度远小于煅烧前的纤维,Ti-O键增强。与TiO2粉体相比,纤维的比表面积大大增加,达到372.67m2/g。在紫外光条件下,TiO2纳米纤维的降解率达到92.3%,比TiO2纳米粉体高出近40%。

The TiO2 nanofibers were successfully synthesized by hydrothermal method. 25ml Potassium hydroxide solution （10mol/L） and titanium dioxide particles of proper quality were mixed as precursor. In this work, Transmission electron microscope （TEM）, X-ray diffraction patterns （XRD）, Fourier-transform infrared spectra （FT-IR） and Specific surface area （BET） were used to investigate the structure, microcosmic morphology and chemical component of the TiO2 nanofibers. The results show that the product was H2Ti3O7. Its structure transformed and the intensity of absorb apex in Fourier-transform infrared spectra depressed after calcined. The aspect ratio of product was attain to 50 and growing uniformly. Compared with titanium dioxide powders, the surface area of TiO2 nanofibers are greatly increased to 372.67m^2/g. The experiment of photocatalytic degradation methylene blue indicated that photocatalytic activity of TiO2 fiber calcined at 550℃ was higher than that of lower concentration when the concentration of organic compound was fixed.