Enhancement of full-spectrum photocatalytic activity over BiPO4/Bi2WO6 clomposites

The full-spectrum photocatalytst is of important value for the practical use, which could absorb natural sunlight for photoctalytic degrading organic pollutants. BiPO4/Bi2WO6 composite photocatalysts were prepared via ultrasonic-calcination method and had superior photocatalytic performance for degrading different kinds of organic pollutants under simulant sunlight irradiation. The apparent rate constant of 5.0%BiPO4/Bi2WO6 on the degradation of methylene blue (MB) is 0.0305 min-1, which is about 25.4 and 3.2 times of pure BiPO4 and Bi2WO6 respectively. In the BiPO4/Bi2WO6 composite photocatalysts, the core-hole structure of BiPO4 as core and Bi2WO6 as hole was formed. During the photocatalytic process of BiPO4/Bi2WO6 composites under simulant sunlight irradiation, the photo-generated electrons of BiPO4 would inject to the conduction band of Bi2WO6, and the photo-generated holes on Bi2WO0 could transfer to the valance band of BiPO4, and then an effective charges separation was achieved. The interaction of BiPO4 and Bi2WO6 not only expanded the range of absorption spectrum but also enhanced the separation efficiency of photo-generated charges, and further improved the photocatalytic performance. (C) 2016 Elsevier B.V. All rights reserved.