Preparation and characterization of novel Ln (Gd3+, Ho3+ and Yb3+)-doped Bi2MoO6 with Aurivillius layered structures and photocatalytic activities under visible light irradiation

Rare earth ions (Ln = Gd3+, Ho3+, Yb3+)-doped Bi2MoO6,(B(2-x)Ln(x)M), with different Ln(3+) contents were successfully synthesized by polymeric precursor method, and characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), scanning electron microscope (SEM), photoluminescence spectra (PL) and energy-dispersive X-ray spectroscopy (EDS). XRD results indicated that the prepared compounds are of Aurivillius layered structures. The DRS results indicated that the Ln(3+) doping increased the visible light absorption ability of B(2-x)Ln(x)M and a red shift was appeared when compared to pure Bi2MoO6. From SEM images it was found that different lanthanides doping leads to various morphology. The photocatalytic activity of prepared compounds was evaluated by the degradation of Rhodamine B (RhB) in aqueous solution under visible light irradiation. The results showed that the doping of the rare earth ions can significantly improve the photocatalytic activity of Bi2MoO6 due to the efficient inhibition of the recombination of photogenerated electron-hole pairs. The effects of concentration of lanthanides ions on the photocatalytic activities of bismuth molybdate are also discussed. (C) 2014 Elsevier B.V. All rights reserved.