Abstract
The impact of a CeO2-ZnO nanocomposite on the photocatalytic and antibacterial properties compared to bare ZnO was investigated. A CeO2-ZnO nanocomposite was synthesized using Acacia nilotica fruit extract as a novel fuel by a simple solution combustion method. The obtained CeO2-ZnO nanocomposite was confirmed structurally by XRD, FTIR, Raman and UV-DRS and morphologically by SEM/TEM analysis. The XRD pattern indicates the presence of both hexagonal Wurtzite-structured ZnO (major) and cubic-phase CeO2(minor). FTIR shows the presence of a Ce-O-Ce vibration at 468 cm(-1)and Zn-O vibration at 445 cm(-1). The existence of a band at 460 cm(-1)confirmed the F(2g)Raman-active mode of the fluorite cubic crystalline structure for CeO2. Diffused reflectance spectroscopy was used to estimate the bandgap (E-g) from Kubelka-Munk (K-M) theory which was found to be 3.4 eV. TEM analysis shows almost spherical-shaped particles, at a size of about 10-15 nm. The CeO2-ZnO nanocomposite shows a good BET specific surface area of 30 m(2)g(-1). The surface defects and porosity of the CeO2-ZnO nanocomposite caused methylene blue (MB) dye to degrade under sunlight (88%) and UV light (92%). The CeO2-ZnO nanocomposite also exhibited considerable antibacterial activity against a pathogenic bacterial strain.