Novel Fabrication and Synthetic Mechanism of CeO_2 Nanorods by a Chloride-Assisted Hydrothermal Method

摘要

CeO_2 nanorods of 15-30 nm in diameter and 100-300 nm in length were successfully synthesized by a novel chloride-assisted hydrothermal synthesis process using CeCI_3 ? 7H_2O as cerium source and N_2H_4 ? H_2O as min-eralizer. The crystal phases, morphology, chemical state, and optical properties of CeO_2 nanostructures were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, X-ray pho-toelectron spectroscopy, UV-vis spectrophotometer and fluorescence spectrometer. Under similar hydrothermal conditions, use of Ce(NO_3)_3 ? 6H_2O instead of CeCI_3 ? 7H_2O as cerium source results in the growth of CeO_2 nanoparticles rather than nanorods. The absorption edge of CeO_2 nanorods showed a blue-shift compared with nanopariticles. Photoluminescence spectra of CeO_2 nanorods exhibited a stronger emission than the nanoparticles. The synthetic mechanism of CeO_2 nanorods has been proposed and can be mainly attributed to the coordination interaction between ethylenediamine and chlorine ions, as well as the effect of anions (Cl‐, OH‐) on the nucleation process and the morphology formation of CeO_2 nanostructures.