Ce掺杂Bi2MoO6/TiO2纳米纤维异质结的制备及可见光催化性能

以静电纺丝技术制备的TiO₂纳米纤维为基质，通过溶剂热法制备了异质结型稀土Ce掺杂Bi₂MoO₆/TiO₂复合纳米纤维。利用X射线衍射（XRD）、扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、透射电镜（TEM）、紫外-可见漫反射光谱（UV-Vis DRS）以及荧光光谱（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为模拟有机污染物，研究了样品的可见光催化性能。结果表明：在稀土掺杂样品中，Ce离子进入Bi₂MoO₆晶格，部分取代Bi³⁺，导致晶胞膨胀，晶格畸变，形成缺陷；与TiO₂复合形成异质结，有利于光生电荷的产生、转移和有效分离，从而提高TiO₂纳米纤维的光催化活性。可见光照射180 min，罗丹明B的降解率达到95.1%。经5次循环光催化降解活性基本不变，样品具有良好的光催化稳定性。

Preparation and Visible-Light Photocatalytic Properties of Ce-doped Bi2MoO6/TiO2 Nanofibers Heterojunction

By employing electrospun TiO₂ nanofiber as substrate, rare earth Ce doped Bi₂MoO₆/TiO₂ composite nanofibers were prepared via solvothermal method. The composition, morphology and optical properties were characterized by XRD, SEM, XPS, TEM, UV-Vis DRS and PL analysis. The photocatalytic properties were tested by degradation of rhodamine B under visible light. The results show that Ce³⁺ ion can be a substitute for Bi³⁺ in the crystal lattice of Bi₂MoO₆, resulting in an expansion, distortion of lattice cell and hence defects. Photocatalytic test shows that the activity of TiO₂ nanofibers under visible light can be enhanced. For example, the degradation percentage of RhB can be as high as 95.1%, which is believed to benefit from the effective charge generation, transfer and separation at the interface of Ce-doped Bi₂MoO₆/TiO₂ heterojunction. Moreover, the Ce-doped Bi₂MoO₆/TiO₂ composite nanofibers are of good stability, whose activity is hardly decreased after cycling 5 times.