High photocatalytic performance of BiOI/Bi2WO6 toward toluene and Reactive Brilliant Red

BiOI sensitized nano-Bi2WO6 photocatalysts with different BiOI contents were successfully synthesized by a facile deposition method at room temperature, and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL) spectra, UV–vis diffuse reflection spectroscopy (UV–vis DRS) and Brunauer–Emmett–Teller (BET) surface area measurements. The photocatalytic activity of BiOI/Bi2WO6 was evaluated by the photo-degradation of Reactive Brilliant Red (X-3B) in suspended solution and toluene in gas phase. It has been shown that the BiOI/Bi2WO6 catalysts exhibit a coexistence of both tetragonal BiOI and orthorhombic Bi2WO6 phases. With increasing BiOI content, the absorption intensity of BiOI/Bi2WO6 catalysts increases in the 380–600 nm region and the absorption edge shifts significantly to longer wavelengths as compared to pure Bi2WO6. The 13.2% BiOI/Bi2WO6 catalyst exhibits obviously higher UV and visible light photocatalytic activities than commercial P25, pure Bi2WO6 and BiOI, for the photodegradation of toluene and X-3B. The remarkably enhanced photocatalytic activities can be attributed to the fact that the proper BiOI sensitized nano-Bi2WO6 increase its BET surface area, decrease band-gap energy, enhance absorption in the 380–600 nm region and inhibit the recombination of photo-induced carriers.