CeO2-ZnO nano composites: Dual-functionality for enhanced photocatalysis and biomedical applications

In present study, we employed a simple and cost-effective chemical precipitation method to synthesize CeO2:ZnO nanocomposites with various Ce:Zn molar ratios. The X-ray diffraction pattern confirms the formation of a cubic structure of CeO2 and a hexagonal wurtzite structure of ZnO in the Ce:Zn nanocomposites. Structural parameters were determined through a Rietveld refinement process using the X-ray diffraction pattern. The elemental composition of the synthesized compounds were assessed using energy-dispersive X-ray spectroscopy (EDX). Raman spectroscopy revealed the presence of the F2g vibrational mode corresponding to CeO2 NPs as well as the E2 mode corresponding to ZnO NPs. Transmission electron microscopy shows the lateral dimensions of both CeO2 and ZnO nanoparticles in the prepared composites. Photoluminescence (PL) spectra were analysed to examine the defects present in the samples. Absorption spectra were recorded in the wavelength range of 325-1100 nm using UV-Vis spectroscopy. The photocatalytic activity of the synthesized samples was studied for the degradation of methylene blue (MB) under UV light irradiation. Among all prepared composites, the Ce: Zn (1:3) nanocomposite showed the highest photodegradation activity (95 %) against the methylene blue (MB) dye. We also examined in detail the anticancer potential of the Ce:Zn composites against human lung carcinoma cells (A549).