Homogeneous core/shell Bi2WO6 spherical photocatalysts: their controlled synthesis and enhanced visible-light photocatalytic performances

In this report, a class of homogeneous core/shell Bi2WO6 spheres was successfully synthesized via mild solvothermal reaction processes in the presence of Polyvinylpyrrolidone (PVP). Moreover, the as-prepared core/shell structure can combine with noble metals such as Au and/or Pt via light-reduction process to form their composite spheres. The obtained Bi2WO6-based samples were characterized by X-ray powder diffraction (XRD), scan electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET), and UV-visible diffuse reflectance techniques. Results demonstrated that the as-prepared Bi2WO6 samples exhibit good crystalline feature. The specific core/shell Bi2WO6-based samples could be employed as visible-light-responsive catalyst towards to decomposition of Rhodamine B (RhB) under visible-light irradiation, their photocatalytic efficiency displays significantly enhancement compared with P25, SSR-Bi2WO6, and/or previously prepared Bi2WO6, which could be attributed to their higher specific surface, unique core/shell structure, and retardation of the recombination of photo-generated holes and electrons. More importantly, the present synthetic approach can be facilitated to prepare novel composite catalysts with specific morphologies and architectures.