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.