Ultrasonic-assisted in-situ fabrication of BiOBr modified Bi 2 O 2 CO 3 microstructure with enhanced photocatalytic performance.

Via an ultrasonic-assisted in-situ etching method, BiOBr modified Bi2 O2 CO3 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 Bi2 O2 CO3 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.