Metathesis synthesis, characterization, spectral and photoactivity studies of Ln2/3MoO4 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y)

Abstract Rare earth ortho-oxomolybdates of composition Ln 2/3 MoO 4 (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er and Y) were prepared by metathesis reaction. All these materials were characterized by powder X-ray diffraction, Fourier transform-infrared spectroscopy (FT-IR) and UV-Vis diffuse reflectance spectra. The Rietveld analysis of all the samples was carried out to obtain the unit cell parameters and reliability factors. All the materials were crystallized in tetragonal lattice with I 4 1 / a space group. The infrared spectra of all the samples were characterized by bands due to MoO 4 2– units. The bandgap energies of all the samples were obtained from UV-Vis DRS spectra. The luminescence spectra of Ln 2/3 MoO 4 (Ln=Pr, Eu and Dy) showed characteristic transitions of the rare earth ions. The visible light photocatalytic activity of all the samples was studied against degradation of methylene blue.