Sunlight-assisted synthesis of cerium (IV) oxide nanostructure with enhanced photocatalytic activity

Abstract In this work, cerium oxide (CeO2) nanostructures have been synthesized using a sunlight-assisted combustion method from cerium nitrate hexahydrate and glycine as precursors. The synthesized sunlight-assisted cerium oxide (CeO2-SA) nanopowder has been characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscope, UV–Visible spectroscopy, Raman spectroscopy, photoluminescence spectroscopy, and Nitrogen adsorption–desorption isotherm. In this method of synthesis, natural sunlight is used as energy source to ignite the reaction and the product is obtained immediately. The synthesized CeO2-SA has a fluorite-like cubic crystal structure and spongy morphology with irregular pores. It is also found that CeO2-SA possesses a smaller particle size, narrower band gap and lower recombination rate than bulk CeO2. The crystalline size of CeO2-SA nanoparticles was obtained to be 4.9 nm. The optical band gap for CeO2-SA was found to be 2.98 eV. The BET Surface area for CeO2-SA was found to be 19.7 m2/g which is 5.3 times greater than the surface area of bulk CeO2 (3.7 m2/g). Around 91% degradation of methylene blue dye (MB) is observed. Therefore, CeO2-SA exhibits higher photocatalytic efficiency towards the degradation of MB than bulk CeO2.