Bi/TiO_2复合纳米纤维制备及可见光催化性能

以电纺TiO_2纳米纤维为基质,EDTA为鳌合剂和吸附剂,采用溶剂热法制备Bi/TiO_2复合纳米纤维光催化材料,利用X射线粉末衍射(XRD)、扫描电镜(SEM)、X射线能量色散谱(EDS)、透射电镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和荧光光谱(PL)等分析测试手段对样品的物相、形貌和光学性能等进行表征,以罗丹明B(Rh B)为模拟有机污染物,考察了样品的光催化性能。结果表明:EDTA在复合纳米纤维的合成过程中起到关键作用,通过改变EDTA的用量可以有效控制纤维表面构筑单质Bi纳米球的大小和覆盖密度。所制备的复合纳米纤维具有良好的可见光催化活性和稳定性,当单质Bi的负载量为65%时光催化活性最强,可见光照射180 min,RhB的降解率达到96.40%,循环使用5次降解率仍保持在91%以上。

Preparation of Bi/TiO2 Composite NFs with Visible-Light Photocatalytic Activity

The Bi/TiO₂ composite nanofibers were prepared by locating the Bi nanoparticles through solvothermal process on the electrospun TiO₂ in the presence of EDTA, which acted as chelating and adsorbent agent. The phase, morphology and optical properties were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, energy dispersive spectroscopy, UV-Vis diffuse reflection spectrum and photoluminescence. The results indicate that EDTA plays an important role in the preparation of the composite nanofibers, which means the size and the density of Bi nanoparticles locating at the surface of the nanofibers could be well controlled by changing the concentration of EDTA. The catalysts exhibit the highest photocatalytic efficiency when the content of Bi is 65%. The RhB was degraded for 96.40% under visible light irradiation for 180 min, and the degradation efficiency remained over 91% after 5 runs, which suggests that the photocatalysts got well photocatalytic activity and stability.