Synthesis of flower‐like WO ₃ /Bi ₂ WO ₆ heterojunction and enhanced photocatalytic degradation for Rhodamine B

Flower‐like Bi ₂ WO ₆ microspheres were prepared by a facile hydrothermal process without any surfactant or template. The WO ₃ /Bi ₂ WO ₆ 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, WO ₃ nanoparticles adhered to the surface of the three‐dimensional flower‐like hierarchical Bi ₂ WO ₆ . The WO ₃ /Bi ₂ WO ₆ samples showed much higher photocatalytic activity than pure Bi ₂ WO ₆ did for Rhodamine B degradation under visible light irradiation. The improved photocatalytic activity is ascribed to the synergic effect between WO ₃ and Bi ₂ WO ₆ 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.