Up-Conversion Luminescence of NaYF₄:Yb³⁺/Er³⁺ Nanoparticles Embedded into PVP Nanotubes with Controllable Diameters

Abstract

NaYF 4 :Yb 3+ /Er 3+ /polyvinylpyrrolidone (PVP) upconversion (UC) luminescent nanotubes were synthesized by the electrospinning technique. The diameters of the nanotubes were controllable by changing the electrospinning voltages. The structure and the optical properties were studied by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra, and fluorescence microscope. The NaYF 4 :Yb 3+ /Er 3+ /PVP nanocomposites simultaneously possessed UC luminescent property, active surfaces and tubular structure. PVP molecules were found to have an important influence on the UC luminescence of NaYF 4 :Yb 3+ /Er 3+ /PVP nanotubes. Compared with those in pure NaYF 4 :Yb 3+ /Er 3+ nanoparticles, the relative intensities of violet, blue, and green to red emissions were increased in NaYF 4 :Yb 3+ /Er 3+ /PVP nanotubes. It is owing to the existence of PVP molecules, which might produce the passivation on NaYF 4 :Yb 3+ /Er 3+ nanoparticles and reduce the nonradiative relaxation of Er 3+ ion. The luminescent nanotubes with desirable UC properties are expected to be applied in biomedicine.

Polyvinyl Pyrrolidone Wrapped Sn Nanoparticles/Carbon Xerogel Composite as Anode Material for High Performance Lithium Ion Batteries

“…30 For the 46% Sn@PVP-CX composite, the similar adsorption peaks can be observed. According to XPS analysis, the content of Sn in the composite is about 46 wt%.…”

β‐NaYF4:Yb3+, Er3+ upconversion microcrystals with both high emission intensity and controlled morphology

“…Except the above illustration, the formation of nanotube morphology is also worthy to note. Crow‐like nanorods and short nanotubes are synthesized by OA or other stabilizing ligands before. Here, we speculate a growth process of the tubelike crystals prepared with MA as ligands.…”

Colloid‐Electrospinning: Fabrication of Multicompartment Nanofibers by the Electrospinning of Organic or/and Inorganic Dispersions and Emulsions

“… Functional nanostructures obtained by colloidal electrospinning a) conductive gold nanowires obtained after removal of the polymer template and annealing of the nanofibers obtained by electrospinning of concentrated gold nanoparticle dispersions;132 b) UC luminescence photograph of NaYF 4 :Yb 3+ /Er 3+ /PVP nanotubes under 980 nm excitation. Reproduced with permission 133. Copyright 2012, American Chemical Society.…”

“…An important application of hierarchically structured or compartmented nanofibers is in the field of catalysis, which can greatly benefit from the enhanced surface‐to‐volume ratio of these substrates 57. The electrospinning of concentrated nanoparticle dispersions (TiO 2 in PVA matrices) followed by calcination allowed the fabrication of nanofibers with narrow polydispersity, displaying tunable mesopores volumes, and diameters 135. This approach is more flexible than the electrospinning of sol–gel precursors (in which a tight control over the environmental humidity is imposed) and therefore it is relevant for the production of easy‐to‐handle, and versatile catalytic substrates.…”