(1. 玉林師范學(xué)院 化學(xué)與材料學(xué)院，玉林 537000；
2. 廣西大學(xué) 廣西理工科學(xué)實(shí)驗(yàn)中心，南寧 530004；
3. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083；
4. 惠州學(xué)院 化學(xué)工程系，惠州 516007)
摘 要: 以表面活性劑聚乙烯吡咯烷酮(PVP)作為結(jié)構(gòu)導(dǎo)向劑，在乙二醇-水混合溶劑熱條件下合成由納米片組裝而成的具有高可見光催化活性的花狀Bi2WO6催化劑。并利用X射線衍射(XRD)、場發(fā)射掃描電鏡(FESEM)、高分辨透射電鏡(HRTEM)、紅外光譜(FTIR)、紫外漫反射(UV-DRS)等測試手段對(duì)催化劑進(jìn)行了表征。結(jié)果表明，降低前驅(qū)液pH值，可得到正交晶系鎢鉍礦型結(jié)構(gòu)的Bi2WO6光催化劑，其中pH值為1.0時(shí)、以1.0 g PVP輔助混合溶劑熱法制備的Bi2WO6晶體呈花狀，其直徑為1.5~2.5 μm。相比未添加PVP制備的片狀Bi2WO6顆粒，花狀Bi2WO6樣品的紫外-可見光吸收邊發(fā)生紅移，其能帶隙減小至2.51 eV，比表面積增大。可見光催化降解甲基橙溶液的結(jié)果表明，以花狀Bi2WO6樣品為光催化劑，可見光照射6 min、濃度為10 mg/L甲基橙溶液的脫色率可達(dá)到100 %，循環(huán)使用5次后其光催化活性并沒有明顯降低，證明Bi2WO6是一種穩(wěn)定有效的實(shí)用可見光催化劑。
關(guān)鍵字: 鎢酸鉍；聚乙烯吡咯烷酮；混合溶劑熱法；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
