Synthesis of nanometer Bi2WO6 synthesized by sol–gel method and its visible-light photocatalytic activity for degradation of 4BS

Nanometer Bi2WO6 catalyst with visible-light responsive was prepared by a sol–gel method in the presence of EDTA. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectrum, Fourier transform infrared (FTIR) spectrum, Brunauer–Emmet–Teller (BET). The UV–vis diffuse reflectance spectrum of the as-prepared sample shows a markedly blue-shift as compared to that of the sample obtained by a solid-state reaction. The as-prepared samples exhibited higher activities than that synthesized by the solid-state reaction for 4BS photodegradation under visible-light irradiation (λ>400 nm) and the sample prepared at 450 °C exhibited the highest photocatalytic activity.