Photocatalytic and photoluminescence properties of CePO4 nanostructures prepared by coprecipitation method and thermal treatment

Abstract

This work deals with the study of the photoluminescence and photocatalytic properties of the two polymorphic phases (hexagonal and monoclinic) of cerium phosphate CePO4 synthesized by facile coprecipitation method, followed by thermal treatments at different temperatures. X-Ray diffraction analyses (XRD) showed the formation of hexagonal then monoclinic nanostructures of CePO4 as calcination temperature increased up to 900 °C. The analysis of diffraction profiles showed the existence of size effects. The resulting morphologies of samples obtained at the various temperatures of 25, 200, 400, 600 and 900 °C were characterized by scanning electron microscopy (SEM). The SEM images indicated increasing particle sizes as thermal treatment temperature increased. The vibration modes were characterized by Fourier transform infrared (FTIR) and Raman spectroscopies. The photocatalytic activities were studied by irradiating aqueous solutions of Rhodamine B with UV light. The best photocatalytic efficiency was observed for the hexagonal nanostructured cerium phosphate prepared at room temperature. Photoluminescence experiments under UV excitation revealed emissions in the violet-blue and red-infrared ranges for the hexagonal and monoclinic phases, with strong intensity for the monoclinic phase obtained at 600 °C.