ZnO修饰提升花状BiOBr的可见光催化降解罗丹明B性能

以Bi(NO₃)₃·5H₂O、Zn(CH₃COO)₂·2H₂O和NaBr为前驱体,采用简单溶剂热法制备BiOBr/ZnO三维花状微纳米复合材料。采用X射线衍射、扫描电子显微镜、X射线光子能谱、N₂吸附-脱附、光致发光和电子顺磁共振等分析技术对其理化性质进行了表征。通过可见光催化降解罗丹明B(RhB)的实验测试了复合材料的光催化性能。结果表明ZnO含量为5%的BiOBr/ZnO光催化活性最优,RhB降解率在50 min后达到98.3%,其降解速率常数是纯ZnO和BiOBr的6.3倍和3.4倍,并且具有较高的稳定性。复合材料光催化性能增强的可能原因为ZnO的引入增强了可见光的吸收和光生载流子的电荷分离效率。

Enhancing Photocatalytic Performance of Flower-like BiOBr for Degradation of Rhodamine B by ZnO Modification

BiOBr/ZnO three-dimensional flower-like nanocomposite with enhanced photocatalytic ability were prepared by simple solvothermal method applying Bi(NO₃)₃·5H₂O, Zn(CH₃COO)₂·2H₂O and NaBr as precursors. The physical and chemical attributes were characterized by various analytical techniques such as X-ray diffraction, scanning electron microscope, X-ray photon spectroscopy, N₂ adsorption-desorption, UV-Vis diffusion reflectance spectroscopy, photoluminescence and electron paramagnetic resonance (EPR). The main crystalline structure of BiOBr is not destroyed after doping, but growth of BiOBr crystals is lightly inhibited by doping ZnO. The trapping agent experiment and EPR spectra show that ·O^2- and ·OH are the main active species in the process of photocatalytic degradation. The photocatalytic activities of the composite were evaluated by the degradation of rhodamine B (RhB) under visible light. The results showed that BiOBr/ZnO with 5% ZnO had the best photocatalytic activity, and the degradation rate of RhB reached 98.3% after 50 min of irradiation. Its degradation rate constant was 6.3 times and 3. 4 times higher than those of pure ZnO and BiOBr, respectively. The introduction of ZnO enhances the absorption of visible light and the charge separation efficiency of photogenerated carriers.