Facile electrospinning fabrication and photoluminescence of LaOI:Tb³⁺ one-dimensional nanomaterials

LaOI:Tb³⁺ nanomaterials including nanofibers, nanobelts, and hollow nanofibers were successfully synthesized by electrospinning combined with a double-crucible iodination method using NH₄I as iodine source for the first time. X-ray diffractometry analysis revealed that LaOI:Tb³⁺ nanostructures were phase-pure tetragonal structure with space group of P4/nmm. Scanning electron microscopy analysis showed that the diameters of LaOI:Tb³⁺ nanofibers, hollow nanofibers and the width of nanobelts were respectively 199.5 ± 30, 376.05 ± 48 nm and 5.2 ± 1.3 μm under the 95 % confidence level. The thickness of the tubewall for hollow nanofibers was 40.5 nm and the thickness of LaOI:Tb³⁺ nanobelts was 154 nm. Photoluminescence (PL) study demonstrated that the LaOI:Tb³⁺ nanomaterials exhibited the emission peaks located at 485, 544, 583 and 625 nm, which were ascribed to ⁵D₃ → ⁷F₁, ₆, ⁵D₄ → ⁷F₅, ⁵D₄ → ⁷F₄ and ⁵D₄ → ⁷F₃ of energy level transitions of Tb³⁺, respectively. The PL intensity was strongly affected by the Tb³⁺-doping concentration, and the optimum quenching concentration was 9 %. The luminescence intensity of LaOI:Tb³⁺ nanofibers was obviously stronger than that of LaOI:Tb³⁺ hollow nanofibers and nanobelts under the same measuring conditions. Commission Internationale de L’Eclairage (CIE) analysis demonstrated that the luminescence color of LaOI:9 % Tb³⁺ nanostructures were located in the green region in CIE chromaticity coordinates diagram. The possible formation mechanisms of LaOI:Tb³⁺ one dimensional nanomaterials were also proposed.