A series of BiOBr catalysts with different microstructures were synthesized by tuning the solvothermal conditions. Assisted by the surface photovoltage, transient photovoltage and time-resolved photoluminescence techniques, the photoexcited charge carriers separation and transfer dynamics were comparatively investigated. The results indicated that the hierarchical BiOBr microflower (BiOBr MF) consisting of well-organized ultrathin nanoflakes were most efficient in promoting charge carrier separation and migration, resulting from the nearly 100 % {001} facets exposed with more oxygen defects. Furthermore, the photocatalytic performance was estimated through the degradation of gaseous ortho-dichlorobenzene (o-DCB) under visible light irradiation, and the BiOBr MF exhibited superior photoactivity. The enhanced mechanism underlying the charge transfer was disclosed by the energy band structures and the reactive oxygen species which were examined by room temperature electron spin resonance. In addition, the catalytic oxidation process of o-DCB over the BiOBr MF and the corresponding surface intermediates was revealed by in situ FTIR spectroscopy.

通过调节溶剂热条件，合成了一系列具有不同微观结构的BiOBr催化剂。借助表面光电压，瞬态光电压和时间分辨光致发光技术，对光激发载流子的分离和转移动力学进行了比较研究。结果表明，由组织良好的超薄纳米薄片组成的分层BiOBr微型花（BiOBr MF）最有效地促进了电荷载流子的分离和迁移，这是由于暴露了更多氧缺陷的近100％{001}面所致。此外，通过气态邻二氯苯（o-DCB），BiOBr MF表现出优异的光活性。通过能带结构和活性氧种类揭示了电荷转移的增强机理，所述能带结构和活性氧种类通过室温电子自旋共振检查。另外，通过原位FTIR光谱揭示了在BiOBr MF和相应的表面中间体上的o- DCB的催化氧化过程。