Self-Assembled 3D Flowerlike Lu₂O₃ and Lu₂O₃:Ln³⁺ (Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) Microarchitectures: Ethylene Glycol-Mediated Hydrothermal Synthesis and Luminescent Properties

Abstract

Three-dimensional flowerlike Lu2O3 and Lu2O3:Ln3+ (Ln = Eu, Tb, Dy, Pr, Sm, Er, Ho, Tm) microarchitectures have been successfully synthesized via ethylene glycol (EG)-mediated hydrothermal method followed by a subsequent heat treatment process. X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectra, thermogravimetric and differential thermal analysis, elemental analysis, inductively coupled plasma atomic absorption spectrometric analysis, ion chromatogram analysis, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, photoluminescence spectra as well kinetic decays, and cathodoluminescence spectra were used to characterize the samples. Hydrothermal temperature, EG, and CH3COONa play critical roles in the formation of the lutetium oxide precursor microflowers. The reaction mechanism and the self-assembly evolution process have been proposed. The as-formed lutetium oxide precursor could transform to Lu2O3 with their original flowerlike morphology and slight shrinkage in the size after postannealing process. The as-obtained flowerlike Lu2O3:Ln3+ samples show strong light emission with different colors corresponding to different Ln3+ ions under ultraviolet−visible light excitation and low-voltage electron beams excitation, which have potential applications in fluorescent lamps and field emission displays.