静电纺丝法制备TiO_2-WO_3纳米纤维及光催化脱汞的研究  

Electrospun TiO_2-WO_3 Nanofibers for Photocatalytic Removal of Mercury

作　　者：袁媛[1] 张军营[1] 樊国祥[1] 赵永椿[1] 郑楚光[1] 

机构地区：[1]煤燃烧国家重点实验室(华中科技大学),湖北省武汉市430074

出　　处：《中国电机工程学报》2012年第32期44-49,8,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(41172140;51176060;51021065)~~

摘　　要：采用静电纺丝法成功制备了TiO2-WO3纳米纤维,利用X-射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscopy,SEM)、紫外可见吸收光谱(ultraviolet-visible,UV-Vis)及比表面积及孔径分析仪(Brunauer-Emmett-Teller,BET)对其进行表征。使用制备的纤维脱除模拟烟气中的元素汞,研究了TiO2-WO3分别在无光、紫外光和可见光下的脱汞率;考察了WO3的最佳掺杂比;并分析了TiO2-WO3光催化脱汞的机制。结果表明TiO2-WO3纤维中TiO2以锐钛矿相形态存在,纤维的直径约为200nm;当WO3的掺杂含量为7%时,TiO2-WO3在紫外光下的汞脱除率可达到100%;TiO2-WO3脱汞效率的稳定性好,在420 min时紫外光下的脱汞率仍保持在100%。表面酸性和有效的电荷转移是TiO2-WO3纳米纤维光催化活性提高的主要原因。TiO2 and TiO2-WO3 nanofibers were successfully prepared by electrospinning method.The nanofibers were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),ultraviolet-visible(UV-Vis) as well as Brunauer-Emmett-Teller(BET).TiO2-WO3 nanofibers were used to remove Hg0from simulated flue gas in the dark,under visible light and UV light respectively.The mercury removal efficiency under different light conditions,the optimum doping content of WO3 as well as the capability to oxidize Hg0 for 8 cycles were tested.The results show that TiO2-WO3 nanofibers exhibit an anatase phase structure with average diameter of 200 nm.The UV-Vis absorption intensity of TiO2-WO3 significantly increases with increasing WO3 doping content.In addition,when the doping content of WO3is 7%,the Hg0 removal efficiency under UV irradiation could reach 100%.After the eighth cycles,the Hg0 removal efficiency over TiO2-WO3 remains at 100%,which indicate that it is stable with prolonged use of the catalysts.The increased photocatalytic activity is attributed to the surface acidity and better photoelectron-hole separation.

关 键 词：TiO2-WO3 纳米纤维 静电纺丝 光催化 脱汞 

分 类 号：X773[环境科学与工程—环境工程] O643.32[理学—物理化学]