CeO2–Al2O3, CeO2–SiO2, CeO2–TiO2 core-shell spheres: formation mechanisms and UV absorption

Abstract

In this work, a general colloid synthesis method for CeO2–Al2O3, CeO2–SiO2, and CeO2–TiO2 core-shell spheres was reported. The properties of these CeO2-based composites were greatly dependent on the additive species. A diffusion-controlled kinetic model was applied to explore the morphology and crystallinity evolution of these core-shell spheres. CeO2–Al2O3 spheres undergo a significant morphology evolution when the Ce/Al molar ratio is varied from 1 : 0.2 to 1 : 1. It also provided an effective way to observe the diffusion channel for mass transport in the diffusion process by dissolving the Al2O3 in CeO2–Al2O3 spheres in alkaline solution. Moreover, a significant composition and structure dependent nature was observed from the UV-vis absorption spectra of these CeO2–Al2O3, CeO2–SiO2, and CeO2–TiO2 core-shell spheres.