Preparation of flower-like BiOBr–WO₃–Bi₂WO₆ ternary hybrid with enhanced visible-light photocatalytic activity

The flower-like BiOBr–WO₃–Bi₂WO₆ (BOB-WO-BWO) ternary hybrids were designed and synthesized by an effective two-step approach. Specifically, WO₃ decorated Bi₂WO₆ were prepared by one-step hydrothermal method and subsequent BiOBr layer via a cost-effective process. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and UV–vis diffuse reflectance spectroscopy (DRS) etc. The results indicated that WO₃ nanoparticles and BiOBr small nanoplates could be dispersed on the surface of flower-like Bi₂WO₆ and the BiOBr–WO₃–Bi₂WO₆ ternary hybrids with suitable BiOBr content showed higher photocatalytic activity than that of pure Bi₂WO₆. The enhanced photocatalytic activity of the BiOBr–WO₃–Bi₂WO₆ was attributed to the cascade electrons transfer from Bi₂WO₆ to BiOBr and then to WO₃ through the interfacial potential gradient in the ternary hybrid which prolong the lifetime of photo-generated charges. The photoluminescence and photo-electrochemical measurement have also verified that the suitable band potential of Bi₂WO₆, WO₃ and BiOBr could help to achieve the efficient separation of photo-generated charges in the composite. - Highlights: • The flower-like BiOBr–WO₃–Bi₂WO₆ ternary hybrids were successfully designed and synthesized. • The BiOBr–WO₃–Bi₂WO₆ showed much higher photocatalytic activity than that of Bi₂WO₆. • The enhanced activity was ascribed to the cascade electron transfer. • A plausible mechanism for ternary hybrids on the degradation of RhB is discussed.