Electrospinning fabrication of color-tunable flexible composite nanofibers containing lanthanide ions

A novel color-tunable PVP/[Tb(BA)₃phen+Eu(BA)₃phen] luminescent composite nanofibers had been fabricated by single axial electrospinning. The morphology and elements components of the as-prepared nanofibers were characterized by field emission scanning electron microscopy and energy dispersive spectroscopy. The luminescent properties were systematically investigated by photoluminescence spectroscopy. The obtained nanofibers had excellent fibrous morphology and smooth surface, and the average diameter was about 200 nm. The novel luminescent composite nanofibers exhibited the green, orange and red fluorescence emission peaks at 490, 545, 592 and 616 nm, which were ascribed to the ⁵D₄ → ⁷F₆ (490 nm) and ⁵D₄ → ⁷F₅ (545 nm) energy transitions of Tb³⁺ ions, and the ⁵D₀ → ⁷F₁ (592 nm), ⁵D₀ → ⁷F₂ (616 nm) transitions of Eu³⁺ ions, respectively. The emitting color of the luminescent composite nanofibers could be tuned by adjusting the mass ratio of terbium complexes and europium complexes in a wide color range of red-yellow-green under the excitation of 274-nm single-wavelength ultraviolet light. The color-tunable luminescent composite nanofibers have potential applications in the fields of display panels, lasers and bioimaging.