Hydrothermal preparation and visible-light photocatalytic activity of Bi2WO6 powders

Bi2WO6 powder photocatalyst was prepared using Bi(NO3)3 and Na2WO4 as raw materials by a simple hydrothermal method at 150 °C for 24 h, and then calcined at 300, 400, 500, 600 and 700 °C for 2 h, respectively. The as-prepared samples were characterized with UV-visible diffuse reflectance spectra, fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 adsorption–desorption measurement. The photocatalytic activity of the samples was evaluated using the photocatalytic oxidation of formaldehyde at room temperature under visible light irradiation. It was found that post-treatment temperature obviously influenced the visible-light photocatalytic activity and physical properties of Bi2WO6 powders. At 500 °C, Bi2WO6 powder photocatalyst showed the highest visible-light photocatalytic activity due to the samples with good crystallization and high BET surface area.