Electrospinning preparation and properties of Fe₃O₄/Eu(BA)₃phen/PVP magnetic-photoluminescent bifunctional composite nanofibers

Europium complex Eu(BA)₃phen (BA = benzoic acid, phen = 1,10-phenanthroline) and ferroferric oxide nanoparticles were incorporated into polyvinyl pyrrolidone (PVP) and electrospun into composite fibers. The average diameter of the composite fibers was about 265 ± 26 nm. The morphology and properties of the final products were investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, and fluorescence spectrometer. Fluorescence emission peaks of Eu³⁺ were observed in the Fe₃O₄/Eu(BA)₃phen/PVP composite nanofibers and assigned to the transitions of ⁵D₀ → ⁷F₀ (581 nm), ⁵D₀ → ⁷F₁ (592 nm), ⁵D₀ → ⁷F₂ (617 nm) of Eu³⁺, and the ⁵D₀ → ⁷F₂ hypersensitive transition at 617 nm was the predominant emission peak. The factors effecting fluorescence intensity were researched through investigation of different ratios of Eu(BA)₃phen to PVP and Fe₃O₄ nanoparticles to PVP. The results indicated that optimum mass percentage of Eu(BA)₃phen to PVP was 15 %. Adding more Fe₃O₄ nanoparticles could enhance saturation magnetization of the composite fibers, but the fluorescence intensity was decreased. The fluorescence and magnetism of the composite nanofibers can be tuned via adding of various amounts of Eu(BA)₃phen and Fe₃O₄ nanoparticles. The new type bifunctional magnetic-photoluminescent Fe₃O₄/Eu(BA)₃phen/PVP composite nanofibers have potential applications in many fields due to their excellent magnetism and fluorescence.