Fabrication of Y2O2S:Eu3+ hollow nanofibers by sulfurization of Y2O3:Eu3+ hollow nanofibers

Abstract

Y 2 O 3 :Eu 3? hollow nanofibers were prepared by calcination of the electrospun PVP/[Y(NO 3 ) 3 ? Eu(NO 3 ) 3 ] composite nanofibers, and then Y 2 O 2 S:Eu 3? hollow nanofibers were successfully synthesized by sulfurization of the as-obtained Y 2 O 3 :Eu 3? hollow nanofibers via a double-crucible method using sulfur powders as sulfur source. The samples were investigated in detail by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and fluorescence spectroscopy. XRD analysis shows that the Y 2 O 2 S:Eu 3? hollow nanofibers are pure hexagonal phase with the space group of P " 3m1. SEM observation indicates that as-prepared Y 2 O 2 S:Eu 3? nanofibers are obvious hollowcentered structure with the mean outer diameter of 184 ± 26 nm. Under the excitation of 260-nm ultraviolet light, the Y 2 O 2 S:Eu 3? hollow nanofibers exhibit red emissions of predominant emission peaks at 628 and 618 nm originated from 5 D 0 ? 7 F 2 energy levels transitions of Eu 3? ions. The luminescent intensity of Y 2 O 2 S:Eu 3? hollow nanofibers is remarkably increased with the increase of doping concentration of Eu 3? ions and reaches a maximum at 3 mol % of Eu 3? ions. The emitting colors of the samples are located in the red region in CIE chromaticity coordinates diagram. The possible formation mechanism of Y 2 O 2 S:Eu 3? hollow nanofibers is also proposed. This preparation technique could be applied to prepare other rare earth oxysulfide hollow nanofibers.

Hydrothermal crystallization of a Ln2(OH)4SO4·nH2O layered compound for a wide range of Ln (Ln = La–Dy), thermolysis, and facile transformation into oxysulfate and oxysulfide phosphors

“…The uorescence decay for both Eu 3+ and Tb 3+ in Gd 2 O 2 SO 4 and Gd 2 O 2 S was found to follow a single exponential mode in each case (Fig. S9 †), and the derived lifetime values are displayed in Table 2 50,51 and 0.78-1.10 ms for (Gd,Tb) 2 O 2 S and (La,Tb) 2 -O 2 S. 51,52 The CIE color coordinates derived from the PL spectra are shown in Table 2 and Fig. S10, † where it can be seen that Tb 3+ and Eu 3+ ions in Gd 2 O 2 S have more green and red components, respectively.…”

Understanding the White-Emitting CaMoO4 Co-Doped Eu3+, Tb3+, and Tm3+ Phosphor through Experiment and Computation

“…Hence, by combining 4f-4f transitions, which exhibit intrinsic luminescence, with 4f-4d transitions, which vary depending on the structure; orange-yellow phosphors with a variety of elements can be developed. This leads to an improvement in the light quality and color reproducibility [47][48] .…”

RE-Based Inorganic-Crystal Nanofibers Produced by Electrospinning for Photonic Applications

“…In fact, Eu 3+ ions, also possess a series of visible emission lines that originate from the 5 D 0 and 5 D 1 multiplets with good color-tuning properties [30,72,82], that make them very interesting for lightening applications. In fact, Eu-doped nanofiber mats have already been tested in realistic LED devices [32,34] and Eu 3+ is probably the mostly studied rare earth ion in nanofiber matrixes [1,13,19,29,30,32,34,35,37,41,42,45,47,48,51,[53][54][55]61,62,67,68,76,[79][80][81][82]84,[86][87][88][89]91,101,112] including some nanobelt structures [72] and hollow structures [82]. In most of these cases, diameter of the nanofibers was less than 300 nm, with a few exceptions [35,42,76].…”