Novel Y doped Bi2WO6 photocatalyst: Hydrothermal fabrication, characterization and enhanced visible-light-driven photocatalytic activity for Rhodamine B degradation and photocurrent generation

Visible-light-driven (VLD) Yttrium (Y) ion doped Bi2WO6 photocatalyst has been synthesized via a facile hydrothermal route. Incorporation of Y3+ into Bi2WO6 lattice was successfully confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ICP analysis. The microstructure and optical property of the as-prepared samples have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption isotherm and UV-vis diffuse reflectance spectra (DRS). The photocatalytic experiments indicated that the Y-Bi2WO6 showed a much higher photocatalytic activity than the pristine Bi2WO6 for the degradation of Rhodamine B (RhB) and photocurrent (PC) generation. This enhancement should be ascribed to the slightly increased band gap and the generated defects by Y3+ doping, thus resulting in a much lower recombination rate of the photoinduced electrons and holes. Such a process was verified by the photoluminescence (PL) spectroscopy. In addition, the active species trapping experiments indicated that holes (h(+)) and superoxide radicals (center dot O-2(-)) play important roles in the photocatalytic reaction. (C) 2015 Elsevier Inc. All rights reserved.