3D介孔TiO_2微米球的制备及其光催化降解双酚A的研究

Preparation of 3D mesoporous titanium dioxide microspheres and its photocatalytic degradation activity on bisphenol A

利用水热方法,无需模板一步合成3D介孔TiO2光催化剂.然后采用X射线衍射(XRD)、透射电子显微镜(TEM)、高分辨电子显微镜(HRTEM)和N2吸附-解吸BET技术对其组织结构进行表征,以双酚A为目标物对比介孔TiO2光催化剂和市售P25的光催化性能,并研究了不同温度下TiO2的相变及热重分析(TGA).结果表明,于400℃焙烧的TiO2介孔微球为锐钛矿型结构,其粒径为4.2nm,比表面积达到159.4m2.g-1.800℃焙烧后的TiO2介孔微球转变为金红石矿型结构.实验表明,以300W高压汞灯为光源进行光催化实验,400℃焙烧后的TiO2介孔微球1h内可使浓度为20mg.L-1BPA溶液的降解率可达100%,高于市售P25粉体的降解率.

The 3D mesoporous TiO2 microspheres were fabricated in a one-step hydrothermal process without templates,and the microspheres were subsequently characterized by XRD,TEM,HRTEM and BET techniques.The photocatalytic degradation activity of the 3D mesoporous TiO2 microspheres was evaluated by comparison to the commercial P25 on the degradation of bisphenol A（2,2-bis（4-hydroxyphenyl） propane,BPA）,and the phase transformation of TiO2 at different temperatures and thermal gravimetric analysis（TGA） were also studied.The results showed that mesoporous TiO2 microspheres calcined at 400 ℃ were anatase phase,with the diameter of 4.2 nm and the specific surface area of 159.4 m2.g-1.The crystal form of mesoporous TiO2 microspheres was transformed into rutile phase under calcination at 800 ℃.The irradiation experiments using a 300 W high pressure mercury lamp as the light source showed that the degradation efficiency of 20 mg.L-1 BPA solution was up to 100% within 1 h using the mesoporous TiO2 microspheres calcined at 400 ℃ as catalyst,which was superior to commercial P25 powders.