Microwave hydrothermal synthesis and visible-light photocatalytic activity of Bi2WO6 nanoplates

Nanosized bismuth tungsten oxide, Bi2WO6, has been successfully synthesized by a microwave hydrothermal approach for the first time, using Bi(NO3)(3), NH3 and H2WO4 as the starting materials. The influences of the reaction conditions (including starting materials, concentration, reaction temperature, and holding time) on the phases and morphologies of the products are investigated by X-ray diffraction and transmission electron microscopy. The best conditions for the synthesis are provided. Transmission electron microscopic results reveal that the as-prepared particles are sheet-shaped. The experiments show that the microwave hydrothermal approach is a satisfactory method for the synthesis of the Bi2WO6 nanocrystals. Meanwhile, the photocatalytic activity of Bi2WO6 nanoplates for the degradation of methylene blue under visible light irradiation (lambda > 400 nm) is much higher than that of samples prepared by the solid-state reaction. (c) 2007 Elsevier B.V. All rights reserved.