Preparation, characterization, photoactivity and XPS studies of Ln2ZrTiO7 (Ln = Sm and Nd)

Oxides of composition Ln2ZrTiO7 (Ln = Sm and Nd) were prepared by sol–gel method and characterized by powder X-ray diffraction (XRD), energy dispersive spectra (EDS), Raman, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These compounds were crystallized in the disordered pyrochlore structure in cubic lattice with image space group. The TEM images of Sm2ZrTiO7 and Nd2ZrTiO7 prepared at 600 °C gave the particle size of 13 and 21 nm respectively. The photocatalytic activity of products was studied using photodegradation of methyl orange under UV light irradiation. The photocatalytic activity of these oxides was found to be less than that of La2Zr2O7 and Nd2Zr2O7. The 3d profile of Nd2ZrTiO7 gave satellite peaks on the low binding energy side in the XPS spectrum which were absent in the XPS spectrum of Sm2ZrTiO7. The reasons for the observation of satellite peaks were given.