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 degrees C for 24 h, and then calcined at 300, 400, 500, 600 and 700 degrees 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 N-2 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 degrees C, Bi2WO6 powder photocatalyst showed the highest visible-light photocatalytic activity due to the samples with good crystallization and high BET surface area. (c) 2005 Elsevier Inc. All rights reserved.