Synthesis and characterization of ultralong La2O3:Eu3+ photoluminescent nanowires

Abstract

Ultralong La₂O₃:Eu³⁺ single-crystalline nanowires were successfully fabricated through a large-scale and facile composite-hydroxide-mediated method followed by a subsequent heat treatment process. The as-synthesized products were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and photoluminescence spectra. The product formed via the composite-hydroxide-mediated method, La(OH)₃:Eu³⁺, can transform into La₂O₃:Eu³⁺ with the same wire-like morphology after a postannealing process. The possible mechanistic pathways for the formation of the one-dimensional (1D) La₂O₃:Eu³⁺ superstructure have been proposed. La(OH)₃:Eu³⁺and La₂O₃:Eu³⁺ nanowires are high-surface-area materials. Under the excitation of 283 nm ultraviolet light, La₂O₃:Eu³⁺ nanowires show a strong red emission line corresponding to ⁵D₀ → ⁷F₂ transition at 625 nm.