Synthesis of flower-like WO3/Bi2WO6 heterojunction and enhanced photocatalytic degradation for Rhodamine B

Flower-like Bi2WO6 microspheres were prepared by a facile hydrothermal process without any surfactant or template. The WO3/Bi2WO6 samples were prepared by a simple heat treatment. The obtained samples were characterised by X-ray diffraction, field emission scanning electron microscopy, photoluminescence spectra, transient photocurrent and UV-vis absorption spectroscopy. In the heterojunctions, WO3 nanoparticles adhered to the surface of the three-dimensional flower-like hierarchical Bi2WO6. The WO3/Bi2WO6 samples showed much higher photocatalytic activity than pure Bi2WO6 did for Rhodamine B degradation under visible light irradiation. The improved photocatalytic activity is ascribed to the synergic effect between WO3 and Bi2WO6 in the framework, which led to the high transfer rate of photoinduced charge carriers. The possible photocatalytic mechanism of the composites is proposed to further understand the improvement in photocatalytic activity.