【摘要】 将碱热法和溶剂热法相结合,制备了不同配比的BiOBr/TiO₂异质结催化剂,采用场发射扫描电子显微镜（FESEM）、透射电镜（TEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、X射线光电子能谱分析（XPS）、紫外可见漫反射光谱（UV-Vis DRS）和光致发光光谱（PL）等技术对其结构、形貌和光学性能进行表征,并探讨BiOBr和TiO₂的配比对罗丹明B（RhB）脱色率的影响。结果显示,该异质结催化剂由锐钛矿相TiO₂纳米颗粒附着生长在BiOBr花状球表面构成;BiOBr和TiO₂摩尔比为1∶2的BiOBr/TiO₂催化剂在可见光照射下催化反应15min,RhB脱色率达96.5%;催化剂循环使用4次后,RhB脱色率仅降低7.94%,稳定性较好。Mott-Schottky曲线表明,该催化剂光催化活性的提升主要是由于在BiOBr和TiO₂界面上形成了p-n结,使电子-空穴对得到有效分离。光催化机理研究结果表明,O·-2是光催化反应过程中的主要活性物种,RhB的脱色主要是由于脱乙基和苯环开环氧化导致。更多还原

【Abstract】 BiOBr/TiO₂ heterojunction catalysts with different ratios were prepared by a combination of alkaline heat and solvothermal methods.And the structures,morphologies and optical properties of the samples were characterized by field emission scanning electron microscope（FESEM）,transmission electron microscope（TEM）,X-ray diffraction（XRD）,Fourier transform infrared spectrometer（FT-IR）,X-ray photoelectron spectroscopy（XPS）,UV-visible diffuse-reflectance spectrum（UV-Vis DRS）and photoluminescence（PL）spectroscopy techniques.The effect of the ratio of BiOBr and TiO₂ on the decolorization rate of RhB was also investigated.The results show that the heterojunction catalyst is composed of anatase phase TiO₂ nanoparticles attached to the surface of the BiOBr flower sphere;and the decolorization rate of RhB reaches 96.5%after 15 minutes of visible-light irradiation with BiOBr/TiO₂ as catalyst（the molar ratio of BiOBr and TiO₂ is 1∶2）;the decolorization rate of RhB reduces by 7.94%after four cycles,which indicates an excellent photocatalytic stability of the catalyst.Moreover,Mott-Schottky plots demonstrate that the enhancement of photocatalytic activity of the catalyst is mainly due to the formation of p-n junctions at the interface between BiOBr and TiO₂,which effectively separates the electron-hole pairs.According to the research results of photocatalytic mechanism,O·-2is the dominant active species in the photocatalysis reaction process,and the decolorization of RhB is mainly caused by the de-ethylation and epoxidation of benzene ring.更多还原