Web Release Date: February 2,
LaF3, CeF3, CeF3:Tb3+, and CeF3:Tb3+@LaF3 (Core-Shell) Nanoplates: Hydrothermal Synthesis and Luminescence Properties
State Key Laboratory of Application of Rare Earth Resources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, and Graduate University of the Chinese Academy of Sciences, Beijing 100049, People's Republic of China
Received: October 12, 2007
In Final Form: December 1, 2007
Abstract:
LaF3, CeF3, CeF3:Tb3+, and CeF3:Tb3+@LaF3 (core-shell) 2D nanoplates have been successfully synthesized by a facile and effective hydrothermal process. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra as well as kinetic decays were used to characterize the samples. The experimental results indicate that the organic additive, trisodium citrate (Cit3-), as a shape modifier has the dynamic effect by adjusting the growth rate of different crystal facets, resulting in forming the anisotropic geometries of the final products. The possible formation mechanisms for different products have been presented. The CeF3, CeF3:Tb3+, and CeF3:Tb3+@LaF3 (core/shell) nanoplates show characteristic emission of Ce3+ (5d-4f) and Tb3+ (f-f), respectively. By coating the LaF3 shell on the surface of the CeF3:Tb3+ core, the distance between the luminescent lanthanide ions is increased and the surface quenchers are decreased, thus reducing the nonradiative pathways. The luminescent intensity and lifetime of the CeF3:Tb3+@LaF3 core/shell nanoplates are enhanced with respect to the bare CeF3:Tb3+ nanoplates.
Download the full text: PDF | HTML
