Constructing the ZnO/BiOBr hierarchical heterojunction for efficient pollutant photodegradation driven by visible-light

The pollutant of photocatalytic degradation is an ideal approach for environmental protection and sustainable economic development. The reasonable design of hierarchical heterojunction photocatalyst is significantly essential to enhance the photocatalytic performance. Herein, a hierarchical n-p ZnO/BiOBr heterojunction is synthesized by a facial sonochemistry and hydrothermal method to photodegrade methyl orange (MO), rhodamine B (RhB) and methylene blue (MB). Therein, a sample optimized for BZ5.0 (the volume of addition of 5.0 mmol NH4Br and 5.0 mmol Bi(NO3)3·5H2O) exhibits the photocatalytic rate for MO is 7.0 and 5.0 times higher than that of P25 and pure BiOBr, respectively. The enhanced photocatalytic performance can be attributed to improve the utilization of visible light, inhibit the recombination of photogenerated electrons, accelerate the transport of reactant molecules, and provide large surface area for photodegradation of pollutants process. This work provides a reasonable strategy to prepare hierarchical heterojunction photocatalyst for the application of photodegradation.