蛋挞状Bi_2WO_6催化剂的制备及其光催化性能

Preparation and Photocatalytic Performance of Egg-tart-like Bi_2WO_6 Catalysts

以Bi（NO3）3·5H20和Na2WO3·2H2O为原料，CTAB为结构导向剂，在混合溶剂热法条件下合成了由纳米片组成的蛋挞状Bi2WO6晶体的新颖结构。采用XRD、FESEM、HRTEM、Raman、BET、UV-DRS等对产品进行表征。结果表明，产物为正交晶系钨铋矿型结构的蛋挞状Bi2WO6晶体，结晶度良好，其直径约为0．5～μm。相比未添加CTAB制备的片状Bi2WO6颗粒，蛋挞状Bi2WO6样品的拉曼光特征峰、紫外-可见光吸收边发生红移，其能带隙减小至2．48 eV，比表面积增大。可见光催化降解甲基橙溶液的结果表明，蛋挞状Bi2WO6光催化效率高，可见光或太阳光照射15min、浓度为10mg·L^-1甲基橙溶液的脱色率为100％，COD去除率为98．2％，循环使用5次之后其光催化活性并没有明显降低。

The new egg-tart-like Bi2WO6 catalysts self-assembled by nanosheets were synthesized through a mixed solvent-thermal method using Bi （NO3 ）3 · 5H2O and Na2WO3 · H20 as raw materials, surfactants （CTAB） as the structure-directing agent. The properties of the as-prepared samples were investigated by XRD, FESEM, HRTEM, Raman, BET, UV-DRS tests. The results show that Bi2WO6 egg tarts with orthorhombic structures, whose diameter varied in the range 0.5 ～ μm, could be obtained via a complex solvothermal route assited by CTAB. Compared with BiEWO6 catalyst synthesized without CTAB, the Raman bands and the absorption band of the Bi2WO6 egg tarts assisted with CTAB showed a significant red-shift and its band gap was narrowed to 2.48 eV and the specific area increased. A much higher photocatalytic activity of the Bi2WO6 egg tarts assisted with CTAB was found, the decolorization ratio is 100% and the COD removal ratio is 98.2% of methyl orange of 10 mg · L^-1 solution after visible light irradiation for 15 min. In addition, after 5 recycles, there was no Significant for degradation decrease in the photocatalytic activitie of Bi2WO6 samples.