Synthesis and luminescence properties of LaOCl:Eu~(3+) nanostructures via the combination of electrospinning with chlorination technique

摘要

LaOCl:Eu~(3+) nanofibers, nanobelts and nano-tubes were prepared by electrospinning combined with a double-crucible chlorination technique using NH_4Cl as chlorinating agent. Different morphologies of LaOCl:Eu~(3+) were obtained via adjusting some of the electrospun parameters. X-ray powder diffraction analysis indicated that LaOCl:Eu~(3+) nanostructures were tetragonal with space group P4mm. Scanning electron microscope analysis and histograms revealed that diameters LaOCl:Eu~(3+) nanofibers and nanotubes, and the width of LaOCl:Eu~(3+) nanobelts were respectively 198.64 ± 15.07, 168.86 ± 24.70 and 2.103 ± 0.3345 μrn under the 95 % confidence level. Transmission electron microscope observation showed that as-obtained LaOCl:Eu~(3+) nanotubes were hollow-centered structure. Photoluminescence (PL) analysis manifested that the LaOCl:Eu~(3+) with different morphologies emitted the predominant emission peaks at 616 and 618 nm originating from the transition ~5D_0 → ~7F_2 of Eu~(3+) ions under the excitation of 283-nm ultraviolet light. It was found that the optimum molar ratio of Eu~(3+)/(La~(3+)+Eu~(3+)) ions was 5 %. LaOCl:Eu~(3+) nanobelts exhibited the strongest PL intensity of the three morphologies under the same doping concentration. CIE analysis demonstrated that color-tuned luminescence can be obtained by changing doping concentration of Eu~(3+) ions and morphologies of nanoma-terials, which could be applied in the fields of optical telecommunication and optoelectronic devices. The possible formation mechanisms of LaOCl:Eu~(3+) nanofibers, nanobelts and nanotubes were also proposed.