Facile electrospinning fabrication and photoluminescence of LaOI:Tb~(3+) one-dimensional nanomaterials

摘要

LaOI:Tb~(3+) nanomaterials including nanofibers, nanobelts, and hollow nanofibers were successfully synthesized by electrospinning combined with a double-crucible iodination method using NH_4I as iodine source for the first time. X-ray diffractometry analysis revealed that LaOI:Tb~(3+) nanostructures were phase-pure tetragonal structure with space group of P4mm. Scanning electron microscopy analysis showed that the diameters of LaOI:Tb~(3+) 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:Tb~(3+) nanobelts was 154 nm. Photoluminescence (PL) study demonstrated that the LaOI:Tb~(3+) nanomaterials exhibited the emission peaks located at 485, 544, 583 and 625 nm, which were ascribed to ~5D_3→ ~7F_(1,6),~5D_4 → ~7F_5, ~5D_4 → ~7F_4 and ~5D_4 → ~7F_3 of energy level transitions of Tb~(3+), respectively. The PL intensity was strongly affected by the Tb~(3+)-doping concentration, and the optimum quenching concentration was 9 %. The luminescence intensity of LaOI:Tb~(3+) nanofibers was obviously stronger than that of LaOI:Tb~(3+) hollow nanofibers and nanobelts under the same measuring conditions. Commission Internationale de L'Eclairage (CIE) analysis demonstrated that the luminescence color of LaOI:9 % Tb~(3+) nanostructures were located in the green region in CIE chromaticity coordinates diagram. The possible formation mechanisms of LaOI:Tb~(3+) one dimensional nanomaterials were also proposed.