(1. 玉林师范学院 化学与材料学院，玉林 537000；
2. 广西大学 广西理工科学实验中心，南宁 530004；
3. 中南大学 粉末冶金国家重点实验室，长沙 410083；
4. 惠州学院 化学工程系，惠州 516007)
摘 要: 以表面活性剂聚乙烯吡咯烷酮(PVP)作为结构导向剂，在乙二醇-水混合溶剂热条件下合成由纳米片组装而成的具有高可见光催化活性的花状Bi2WO6催化剂。并利用X射线衍射(XRD)、场发射扫描电镜(FESEM)、高分辨透射电镜(HRTEM)、红外光谱(FTIR)、紫外漫反射(UV-DRS)等测试手段对催化剂进行了表征。结果表明，降低前驱液pH值，可得到正交晶系钨铋矿型结构的Bi2WO6光催化剂，其中pH值为1.0时、以1.0 g PVP辅助混合溶剂热法制备的Bi2WO6晶体呈花状，其直径为1.5~2.5 μm。相比未添加PVP制备的片状Bi2WO6颗粒，花状Bi2WO6样品的紫外-可见光吸收边发生红移，其能带隙减小至2.51 eV，比表面积增大。可见光催化降解甲基橙溶液的结果表明，以花状Bi2WO6样品为光催化剂，可见光照射6 min、浓度为10 mg/L甲基橙溶液的脱色率可达到100 %，循环使用5次后其光催化活性并没有明显降低，证明Bi2WO6是一种稳定有效的实用可见光催化剂。
关键字: 钨酸铋；聚乙烯吡咯烷酮；混合溶剂热法；光催化活性
（1. College of Chemistry and Material, Yulin Normal University, Yulin 537000, China;
2. Guangxi Experiment Centre of Science and Technology，Guangxi University，Nanning 530004, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China；
4. Department of Chemical Engineering, Huizhou University, Huizhou 516007, China）
Abstract:The flower-like Bi2WO6 porous microspheres self-assembled by nanosheets were synthesized through a complex solvothermal process using surfactants PVP as the structure-directing agent. The properties of the as-prepared samples were investigated by X-ray diffractometry (XRD), field emission scan electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectrometry (FTIR) and UV-Vis diffusion reflectance spectra (UV-DRS) tests. The results show that Bi2WO6 with orthorhombic structures can be obtained through reducing the pH value of precursor solution. Under the pH values of 1.0, the Bi2WO6 flowers with diameter varied in the range of 1.5-2.5 μm can be obtained via a complex solvothermal route assisted by 1.0 g PVP. Compared with Bi2WO6 catalyst synthesized without PVP, the absorption band of the Bi2WO6 flowers assisted with PVP shows a significant red-shift and its band gap is narrowed to 2.51 eV and the specific surface area increases. The photocatalytic activity of the Bi2WO6 flowers assisted with 1.0 g PVP reaches 100% discoloration rate when 10 mg/L methyl orange solution is irradiated by visible light irradiation for 6 min. In addition, after 5 recycles, there is no significant degradation decrease in the photocatalytic activities of Bi2WO6 samples, indicating that the Bi2WO6 is a stable, effective and useful photocatalyst for the degradation of methyl orange under visible light irradiation.
Key words: Bi2WO6; polyvinyl pyrrolidone; complex solvothermal; photocatalytic activity
