Rapid sonochemical synthesis of irregular nanolaminar-like Bi2WO6 as efficient visible-light-active photocatalysts

Irregular Bi2WO6 nanolaminars have been successfully synthesized via a rapid sonochemical approach using bismuth nitrate and tungstic acid as precursors in an aqueous solution. The characteristics of them were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, pore value, PL spectroscopy and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). These irregular nanolaminars are of geometric shapes of orthorhombic Bi2WO6 with their basal plane being (0 0 1). They possess high crystallinity, lager surface area and pore value, which means fewer traps and stronger photocatalytic activity. The growth mechanism of such special nanolaminar was related to the sonochemical synthesis route, which played a key role in the formation of Bi2WO6 nanolaminar. Simultaneously, it was found that the formation of Bi2WO6 nanolaminar is a time dependent process. The Bi2WO6 nanolaminar has higher photocatalytic activity than bulk Bi2WO6 nanoparticle obtained by refluxing method for rhodamine B (Rh.B) degradation under visible light irradiation (λ > 400 nm).