Hydrothermal synthesis of hierarchically structured cobalt doped bismuth tungstate with improved photocatalytic activity

In the present work, photocatalytic activity of cobalt doped bismuth tungstate nanostructures are reported for the first time. Hydrothermal method was adopted for the synthesis of pristine and Co2+ doped Bi2WO6 nanostructures. The synthesized nanostructures were characterized by X-ray diffraction (XRD), Field emission scanning and transmission electron microscopies (FESEM and TEM), ultraviolet–visible diffuse reflectance spectroscopy (UV-DRS) and Fourier-transform infrared spectroscopy (FTIR). XRD pattern reveals the crystal structure to be orthorombic. The incorporation of dopant leads to the destruction of surface morphology of Bi2WO6 nanostructures. From the DRS spectra it is clear that the dopant has shifted the absorbance of nanostructures to lower wavelength. The synthesized nanostructures exhibit excellent photocatalytic activity against the photodegradation of rhodamine B (RhB) under visible light irradiation. Bi2WO6 with 0.15 and 0.20 mol % cobalt possess better photocatalytic activity among the synthesized nanostructures.