g-C_(3)N_(4)/CeO_(2)/BiOBr三相复合材料的制备及其可见光催化降解RhB性能

Preparation of g-C_(3)N_(4)/CeO_(2)/BiOBr composite and its photocatalytic degradation property for RhB under visible light

以多孔层状g-C_(3)N_(4)为基体,引入沉淀法所得的CeO_(2)/BiOBr复合材料,经超声搅拌制得具有异质结结构的g-C_(3)N_(4)/CeO_(2)/BiOBr三相复合材料。采用X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、紫外-可见光漫反射光谱、光致发光光谱等方法对g-C_(3)N_(4)/CeO_(2)/BiOBr进行了成分、结构和光学性质表征。结果表明:g-C_(3)N_(4)/CeO_(2)/BiOBr三相复合材料呈三明治层状堆叠结构,界面结构构建良好,光响应性能优异,各相分布均匀且结晶程度较高。当Ce∶Bi摩尔比为1∶1,g-C_(3)N_(4)质量分数为15%时所得三相复合材料表现出最高的光催化活性,RhB降解率高达99%,降解速率是纯相CeO_(2)的86倍、纯相BiOBr的3倍。此外,经过4次循环后,复合材料的RhB降解效率依然保持在89%,表现出良好的稳定性。

Porous layered g-C_(3)N_(4) was selected as base material via direct calcination method to synthesize g-C_(3)N_(4)/CeO_(2)/BiOBr ternary composite photocatalytic materials with heterogeneous structure,while CeO_(2)/BiOBr composites were introduced by ultrasonic stirring method.The composition,structure and optical properties of g-C_(3)N_(4)/CeO_(2)/BiOBr were characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray photoelectron spectroscopy,UV-Vis DRS and photoluminescence analysis,and so on.The results show that the g-C_(3)N_(4)/CeO_(2)/BiOBr has sandwich layered stacking structure,good interface contact structure and excellent light response performance due to the uniform phase distribution and high degree of crystallization.When the molar fraction of Ce∶Bi is 1∶1 and the mass fraction of g-C_(3)N_(4) is 15%,the obtained three-phase composite shows the highest photocatalytic degradation property for RhB.The degradation rate for RhB is 99%,which is 86 times that of pure CeO_(2) and 3 times that of pure BiOBr.In addition,the composite has good stability with the RhB degradation efficiency of 89%after four cycles.