Fabrication And Luminescent Properties Of Rare Earth Fluorides Hollow Nanofibers

Rare earth fluorides have become one of the most important matrixes for lanthanide cations-doped phosphors owing to their unique physical and chemical properties. Nowadays, rare earth fluoride nanomaterials with various morphologies including nanoparticles, nanobundles, nanoplates, nanorods, and nanoflowers have been prepared. There have been no reports on the rare earth trifluoride hollow nanofibers. Electrospinning has been proved to be one of the best methods to fabricate low-dimensional nanomaterials owing to its simple operation, high efficiency and reproducibility. Hence, fabrication of rare earth ions-doped rare earth trifluoride luminescent hollow nanofibers via electrospinning remains an important and challenging subject of study.In this dissertation, the precursor spinning solutions were firstly prepared, and PVP/rare earth nitrates composite nanofibers were fabricated by coaxial electrospinning, and then Y2O3:RE3+luminescent hollow nanofibers were prepared through calcining the as-obtained composite nanofibers. For the first time, YF3：RE3+(RE=Eu,Tb) luminescent hollow nanofibers were successfully synthesized via fluorination of Y2O3:RE3+luminescent hollow nanofibers via a double-crucible method we newly proposed. By change of the percentages of PVP and rare earth nitrates in precursor solution, YF3:RE3+(RE=Eu,Tb,Er,Yb/Er) luminescent hollow nanofibers and YF3:Er3+luminescent nanofibers were fabricated via monoaxial electrospinning combined with double-crucible fluorination technique for the first time.The samples were systematically characterized by XRD, SEM, TEM, PL. The results show that YF3:RE3+(RE=Eu,Tb,Er,Yb/Er) hollow nanofibers are pure orthorhombic structure with space group Pnma. The mean diameter of YF3:RE3+hollow nanofibers is about80-250nm. The fluorescent spectra results show that YF3:RE3+hollow nanofibers are very good fluorescent nanomaterials. Possible formation mechanism of rare earth fluoride hollow nanofibers is also presented and some meaningful results are obtained. These findings lay solid foundations for the future study of luminescence of rare earth ions-doped rare earth trifluorides low-dimensional nanomaterials.