Via an ultrasonic-assisted in-situ etching method, BiOBr modified Bi₂O₂CO₃ microstructures were fabricated in short time. The samples were characterized by XRD, SEM, TEM, BET, UV-Vis, XPS and PL spectra methods. Rhodamine B (RhB) aqueous solution was applied to evaluate the photocatalytic activities of the as-prepared samples. The results showed that the sample prepared at pH of 2 in which the molar ratio of BiOBr and Bi₂O₂CO₃ was 0.69:1 had the largest specific surface area, the best utilization for ultraviolet and visible light and efficient separation efficiency of charge carriers, contributing to its best photocatalytic activity.

•O₂^- was proved to be main active species in RhB photodegradation process. Last, the photocatalytic mechanism of the composite was discussed in detail.

通过超声辅助原位刻蚀方法，在短时间内制备了BiOBr改性的Bi ₂ O ₂ CO ₃微结构。通过XRD，SEM，TEM，BET，UV-Vis，XPS和PL光谱法对样品进行表征。罗丹明B（RhB）水溶液用于评估所制备样品的光催化活性。结果表明，在BiOBr与Bi ₂ O ₂ CO ₃的摩尔比为0.69：1的pH值为2的条件下制备的样品具有最大的比表面积，对紫外线和可见光的最佳利用以及有效的电荷分离效率载体，使其具有最佳的光催化活性。

•Ø ₂ ^-被证明是在光降解罗丹明B过程的主要活性物质。最后，对复合材料的光催化机理进行了详细的讨论。