Bi_(20)TiO_(32)/聚丙烯腈复合纳米纤维的制备及其对异丙隆的光催化降解性能

采用溶剂热法制备了可见光响应型光催化剂Bi_(20)TiO_(32),为了实现该光催化剂的固定化负载,进一步以Bi_(20)TiO_(32)和聚丙烯腈(PAN)为原料,通过同轴静电纺丝法制备了不同光催化剂含量的Bi_(20)TiO_(32)/PAN复合纳米纤维。通过这一途径一方面可以便于光催化剂的回收利用,另一方面纳米纤维结构可以提高光催化剂与有机污染物反应的接触面积。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见漫反射光谱(UV-Vis DRS)和氮气吸附-脱附法对样品的物相组成、形貌结构、光谱吸收和比表面积等进行表征。研究了在可见光照射下Bi_(20)TiO_(32)/PAN复合纳米纤维膜对苯脲类农药异丙隆的光催化降解性能。结果显示,制备的Bi_(20)TiO_(32)光催化剂禁带宽度为2.35 eV,属于典型的可见光响应型光催化剂。制备的Bi_(20)TiO_(32)/PAN复合纳米纤维直径在600~700 nm,Bi_(20)TiO_(32)可以在纳米纤维表面均匀负载,复合纳米纤维膜对可见光具有明显的响应性,对异丙隆具有很好的光催化降解效果,其中光催化剂质量分数为25.7%的样品S3对异丙隆的降解率最高可达到87%。这一研究表明,通过同轴静电纺丝法将光催化剂负载于有机纳米纤维表面,可以保持光催化剂原有光催化效果,是实现光催化剂固定化一条较好的途径。

Preparation of Bi20TiO32/Polyacrylonitrile Composite Nanofibers and Their Photocatalytic Activity for Degradation of Isoproturon

Visible-light responsive photocatalyst Bi₂₀TiO₃₂ was prepared through solvothermal method. To achieve the immobilization of photocatalysts, Bi₂₀TiO₃₂/polyacrylonitrile(PAN) composite nanofibers with different content of Bi₂₀TiO₃₂ were prepared by coaxial electrospinning method. Through this approach, the photocatalysts could be easily recycled, meanwhile, the contact area between photocatalysts and organic pollutants was enhanced during the degradation reaction. The prepared samples were characterized by X-ray diffraction spectra(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), ultraviolet-visible(UV-Vis) diffuse reflectance spectra(UV-Vis DRS) and N₂ adsorption-desorption analysis. The photocatalytic activities of Bi₂₀TiO₃₂/PAN composite nanofibers were evaluated by the degradation of isoproturon herbicide under visible-light irradiation. The results show that the prepared Bi₂₀TiO₃₂ photocatalyst with a band gap energy 2.35 eV has a typical visible-light responsive property. The diameters of Bi₂₀TiO₃₂/PAN composite nanofibers are 600~700 nm. Bi₂₀TiO₃₂ is successfully loaded on the surface of nanofibers by this method and the composite materials have obvious visible-light responsibilities. The prepared samples exhibit great photocatalytic activity for degradation of isoproturon. The sample S3 at photocatalyst content 25.7% exhibits the highest removal efficiency of 87%. This research indicates that the photocatalysts immobilized on the organic nanofibers surface can retain their original photocatalytic activity. Coaxial electrospinning technology is a proper approach for the immobilization of photocatalysts.