Low temperature synthesis of fluorite-type Ce-based oxides of composition $$\hbox {Ln}_{2}\hbox {Ce}_{2} \hbox {O}_{7}$$ Ln 2 Ce 2 O 7 ( $$\hbox {Ln} = \hbox {Pr}$$ Ln = Pr , Nd and Eu): photodegradation and Luminescence studies

Abstract

In this work, we have studied the structural behavior of Fluortie-type (F-type) Ce-based oxides of compositions $$\hbox {Ln}_{2}\hbox {Ce}_{2}\hbox {O}_{7}$$ ( $$\hbox {Ln} = \hbox {Pr}$$ , Nd and Eu). F-type oxides can be considered as multi-functional materials due to the deficiency of anions. $$\hbox {Pr}_{2}\hbox {Ce}_{2}\hbox {O}_{7}$$ (PCO), $$\hbox {Nd}_{2}\hbox {Ce}_{2}\hbox {O}_{7}$$ (NCO) and $$\hbox {Eu}_{2}\hbox {Ce}_{2}\hbox {O}_{7}$$ (ECO) were prepared by ethylene glycol-assisted sol–gel method. The structural investigation of these oxides was carried out by Powder XRD and Rietveld refinement. All the materials were found to crystallize in the cubic lattice with space group $$Fm{\overline{3}}m$$ . Raman spectra of these materials are reliable with their XRD data. The morphology and bandgap energy of all the samples were obtained from SEM and KM plot, respectively. The visible light photocatalytic performance of these oxides was examined against the degradation of methylene blue under ambient conditions. The photoluminescence property of the rare earth ions was also studied, and the color coordinates were calculated using CIE 1931 chromaticity. Synopsis Fluorite ( $$\hbox {AO}_{2}$$ , (a)) geometry can be explained as a face centered cubic arrangement of the cations with the anions filling all the tetrahedral spaces with $$Fm{\overline{3}} m$$ space group. Fluorite with one-eighth of anion deficiency leads to P-type oxides with space group $$Fd{\overline{3}}m$$ (b) and C-type oxides with space group Ia3 (c).