Coaxial electrospinning preparation and properties of magnetic–photoluminescent bifunctional CoFe₂O₄@Y₂O₃:Eu³⁺ coaxial nanofibers

CoFe₂O₄@Y₂O₃:Eu³⁺ magnetic–fluorescent bifunctional coaxial nanofibers have been successfully obtained via calcination of the [CoFe₂O₄/PVP]@[(Y(NO₃)₃ + Eu(NO₃)₃)/PVP] composite coaxial nanofibers which were fabricated by coaxial electrospinning technique. The diameter of CoFe₂O₄@Y₂O₃:5 %Eu³⁺ magnetic–fluorescent bifunctional coaxial nanofibers was 133 ± 17 nm. Strong fluorescence emission peaks of Eu³⁺ in the CoFe₂O₄@Y₂O₃:Eu³⁺ coaxial nanofibers were observed and assigned to ⁵D₀ → ⁷F₁ (588 nm), ⁵D₀ → ⁷F₁ (593 nm), ⁵D₀ → ⁷F₁ (599 nm), ⁵D₀ → ⁷F₂ (612 nm) and ⁵D₀ → ⁷F₂ (630 nm) energy levels transitions of Eu³⁺ ions, and the predominant emission peak was located at 612 nm. Compared with CoFe₂O₄/Y₂O₃:Eu³⁺ composite nanofibers, CoFe₂O₄@Y₂O₃:Eu³⁺ magnetic–fluorescent bifunctional coaxial nanofibers simultaneously provided higher magnetism and fluorescent intensity. The color, photoluminescent intensity and magnetism of the coaxial nanofibers can be tuned via adjusting the diversity and content of fluorescent compounds and the content of magnetic compounds. Formation mechanism of CoFe₂O₄@Y₂O₃:Eu³⁺ coaxial nanofibers was also presented. The bifunctional magnetic–photoluminescent CoFe₂O₄@Y₂O₃:Eu³⁺ coaxial nanofibers have potential applications in many fields due to their excellent magnetism and fluorescence.