Synthesis of a hierarchical BiOBr nanodots/BiWO p-n heterostructure with enhanced photoinduced electric and photocatalytic degradation performance

Three-dimensional composites of flower-like Bi 2 WO 6 decorated with BiOBr nanodots (designated BiOBr nanodots/Bi 2 WO 6 ) with varying BiOBr content have been prepared by a simple method. The BiOBr nanodots, with average diameters of 50 nm, adhered tightly to the surface of Bi 2 WO 6 and formed p-n heterojunctions between BiOBr and Bi 2 WO 6 , as evidenced by the characterization of its structure and composition. Compared to pure Bi 2 WO 6 and BiOBr, BiOBr/Bi 2 WO 6 showed a lower charge-transfer resistance, higher photocurrent and enhanced photoelectric properties. The photocurrent of the 15% BiOBr/Bi 2 WO 6 composite was 17.2 and 2.39 times higher than that of pure Bi 2 WO 6 and BiOBr, respectively. Meanwhile, this composite showed the highest degradation rate for methylene blue (MB), which was 1.7 and 2.4 times that of pure Bi 2 WO 6 and BiOBr, respectively. The enhanced photoelectric and photocatalytic degradation performances were ascribed to the introduction of BiOBr nanodots and the formation of p-n heterojunctions, which could greatly accelerate the separation of photogenerated charge carriers. In addition, the roles of the radical species were investigated, and ·O 2 − and h + are thought to dominate the photocatalytic process. Based on the experimental results, a possible photocatalytic mechanism was proposed. Three-dimensional composites of flower-like Bi 2 WO 6 decorated with BiOBr nanodots (designated BiOBr nanodots/Bi 2 WO 6 ) with varying BiOBr content have been prepared by a simple method.