Characterization and Optical Properties of Three Dimensional (3D) CeO2 Microstructures Synthesized by a Template-Free Method

Resumo

Three dimensional (3D) of CeO₂ nanostructures such as convex lens-like, hollow triangular prism, broccolilike, grapelike CeO₂ have been successfully synthesized by cerium carbonate hydroxide (CeOHCO₃) precursors, which were prepared by a hydrolysis process followed by a facile hydrothermal method without using any template or surfactant. The influence of urea amount on CeO₂ nanostructures was discussed. The synthesizing mechanism and the morphological evolution of CeOHCO₃ and CeO₂ were proposed. The CeO₂ samples were examined by XRD, SEM, TEM, UV–Vis, PL, and Raman scattering. The UV–Vis absorption spectrum of the CeO₂ samples showed that the band gap energy (E_g) in rang of 2.6–2.9 eV, which is lower than that of bulk ceria.