Preparation and Characterization of Rare Earth Ions Doped Fluoride Core-Shell up-Conversion Luminescence Nanomaterials

2012 ◽  
Vol 512-515 ◽  
pp. 1972-1975
Author(s):  
Jun Zhang ◽  
Hai Ou Shen ◽  
Shun Hao Wang ◽  
Yan Li Li ◽  
Hui Xin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Ions ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Application Range ◽  
Transmission Electron ◽  
Heterogeneous Layer ◽  
Core Nanoparticles

Coating a heterogeneous layer outside the core nanoparticles has become a common method to protect the properties of nanoparticles and may extend the application range of core nanoparticles. Rare earth ion-doped nanoparticles NaYF4:Yb 3+ ,Er 3+ is one of the most efficient up-conversion nanosystems. In this work, a multi-functional NaYF4:Yb 3+ ,Er 3+ @TiO2 core-shell structure nanocomposite was synthesized. The structure, optical and photoluminescence properties of the up-converting nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and room temperature up-conversion luminescence (UCL) spectrofluorimetric measurements.

Synthesis and Characterization of Rare Earth (Tb3+ and Yb3+) Doped CdS/ZnS Core/Shell Nanocrystals for Enhanced Photovoltaic Efficiency

2011 ◽  
Vol 1322 ◽  
Author(s):  
Sandip Das ◽  
Krishna C. Mandal
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Broadband Absorption ◽  
Photovoltaic Efficiency ◽  
Transmission Electron

ABSTRACTCdS host nanocrystals with 4.2-5.5 nm in diameter have been synthesized from air stable precursors via a synthetic chemical route and doped with rare earth (RE) terbium (Tb3+) and ytterbium (Yb3+) ions. RE3+-doped CdS cores were shelled by ZnS layers of different thicknesses. The resulting core/shell nanocrystals show a complete broadband absorption below 400-460 nm to the deep UV region depending on the size of the cores. RE3+-doped CdS nanocrystals showed a red shift in the emission as observed under irradiation of 302 nm UV light and was confirmed by room temperature photoluminescence (PL) measurements. The nanocrystals were further characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), and energy dispersive x-ray (EDX) analysis. The results show that these RE3+-doped nanocrystals can be used as solar spectral matching downconversion material to enhance photovoltaic efficiency of existing solar cells.

scholarly journals Synthesis and characterization of lanthanum- and yttrium-doped Fe2O3 pigments

Cerâmica ◽  
2007 ◽  
Vol 53 (325) ◽  
pp. 79-82 ◽  
Author(s):  
D. M. A. Melo ◽  
M. A .F. Melo ◽  
A. E. Martinelli ◽  
Z. R. Silva ◽  
J. D. Cunha ◽  
...  
Keyword(s):  
Rare Earth ◽  
Calcination Temperature ◽  
Structural Changes ◽  
Pechini Method ◽  
Color Stability ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Uv Visible

Iron oxide has been doped with rare earth ions (yttrium or lanthanum) aiming at producing ceramic pigments with hues that vary from orange to brown. The powders were synthesized from polymeric precursors using the Pechini method and subsequently calcined between 900 and 1100 ºC. The resulting pigments were characterized by BET, X ray diffraction, colorimetric analysis, UV-visible, infrared (FTIR), particle size distribution and thermal analysis. The color depicted by La/Fe powders changed as the calcination temperature increased from 900 ºC to 1100 ºC, as established by the corresponding changes in the values of the colorimetric coordinates from L* a* b* = 49.003, 10.541, 12.609 to L* a* b* = 31.279, 6.096, 6.877. On the other hand, Y/Fe powders were little affected by similar changes in the calcination temperature, revealing the effect of yttrium on the color stability of the powder. The values of the colorimetric coordinates in this case varied from L* a* b* = 45.230, 17.315, 28.750 to L* a* b* =51.631, 15.726, 25.825. Structural changes were also noticed as a function of the size of the rare earth ion added to the structure. Upon calcination at 900°C, lanthanum stabilized the ABO3-type perovskite structure whereas the presence of yttrium resulted in a mixture of oxides.

Synthesis, Morphology Control and Luminescent Properties of Rare Earth Ion-Doped CaWO4 Microstructures

2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Uv Light ◽  
Luminescent Properties ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Rare Earth Ion ◽  
X Ray ◽  
Facile Hydrothermal Route

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.

scholarly journals Synthesis and Characterization of Sr2CeO4 Phosphor Doped with Erbium

2010 ◽  
Vol 13 (1-2) ◽  
pp. 17
Author(s):  
K.V.R. Murthy ◽  
K. Suresh ◽  
B. Nageswara Rao ◽  
B. Walter Ratna Kumar ◽  
Ch. Atchyutha Rao ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Sem Analysis ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Pl Emission

<p>The present paper reports the Photoluminescence (PL) of the Sr<sub>2</sub>CeO<sub>4</sub> phosphor, singly doped with Erbium rare-earth ion with different concentrations (0.01, 0.1, 0.2, 0.5 and 1%).The phosphor samples were synthesized using the standard solid state reaction technique. The effect of Er dopant on the structural, morphological, and Photoluminescent properties of the samples are studied with X-ray diffraction (XRD), PL and SEM analysis. The PL emission of undoped Sr<sub>2</sub>CeO<sub>4</sub> phosphor was observed at 470 nm with high intensity followed by the primary Er emissions with good intensity at 525, 530, 549, 557 and 565 nm.</p>

Modified TiO2Structures with Enhanced Photoluminescence and Photocatalytic Activity

2021 ◽  
Vol 13 (2) ◽  
pp. 331-341
Author(s):  
Jinqi Wang ◽  
Guopeng Li ◽  
Wei Wang ◽  
Fuxia Li ◽  
Chuankai Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Rare Earth ◽  
Photocatalytic Degradation ◽  
Environmental Remediation ◽  
Rare Earth Ions ◽  
Shell Structures ◽  
Rare Earth Complex ◽  
Core Shell ◽  
Rare Earth Ion ◽  
The Rare Earth

Photocatalytic degradation of pollutants has attracted much attention because it can effectively solve the problem of environmental pollution. SiO2@Eu(TTA)3phen@TiO2 core-shell structures were successfully synthesized for the first time by a solvothermal method involving ultrasound assistance which can optimize the rare earth complex dispersibility and achieve strong emission intensity. SiO2@Eu3+@TiO2 core-shell structures were also successfully synthesized by a similar method. Photocatalytic activity analysis showed that the photocatalytic activity factor not only depended on the rare earth ion content, but also related to the structure and size of the TiO2 nanoparticles. Photocatalytic activity increased first and then decreased with the quantity of rare earth ions. Photocatalytic activity was also superior for hollow structures compared to solid structure. Photocatalytic activity of SiO2@TiO2 particles increased with the particle size, until the size increased to 450 nm. Rare earth ions content as well as particle structures and sizes affected efficiency for the photocatalytic degradation of methyl orange. Outstanding photocatalytic activity provides the composite particles with improved potential to purify aquatic contaminants and to meet the demands of future environmental remediation applications.

Synthesis and Characterization of Carbon-Encapsulated Nickel Nanoparticles from De-Oiled Asphalt

2013 ◽  
Vol 652-654 ◽  
pp. 202-205
Author(s):  
Jun Yu ◽  
Bing She Xu
Keyword(s):  
Nickel Nanoparticles ◽  
Carbon Matrix ◽  
Core Shell ◽  
Ni Nanoparticles ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Nickel Powders ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Carbon-encapsulated Ni nanoparticles with the size of 5 to 30 nm were synthesized from de-oiled asphalt (DOA) by heat-treatment at 1800 °C with nickel powder. The nanoparticles exhibited well-constructed core-shell structures, with Ni cores and graphitic shells. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) examinations confirmed that the carbon-encapsulated Ni nanoparticles were uniformly dispersed in carbon matrix and the Ni nanoparticles were surrounded by several carbon layers with well ordered arrangement. The formation of the core-shell nanoparticles was selectively controlled by adjusting the ratio of de-oiled asphalt to nickel powders. The possible growth model for the carbon-encapsulated Ni nanoparticles was discussed briefly. This result presents a simple and controllable way to synthesize carbon-encapsulated nickel nanoparticles.

Preparation and Characterization of Gold-Loaded Magnetite/Silica Core-Shell Composites

2016 ◽  
Vol 42 ◽  
pp. 47-52
Author(s):  
Dan Dan Huang ◽  
Zhao Dai ◽  
Kun Yang ◽  
Yuan Yuan Chu
Keyword(s):  
Room Temperature ◽  
Solvothermal Reaction ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Transmission Electron ◽  
Silica Core ◽  
Shell Particles

The fabrication of gold-loaded magnetite/silica core-shell particles was presented in this paper. First, 250 nm of magnetic Fe3O4 nanoparticles were prepared by solvothermal reaction. Then, the Fe3O4 particles were coated by SiO2, and Au nanoparticles (AuNPs), respectively. The core-shell structure of these microspheres was confirmed by transmission electron microscopy (TEM) and Power X-ray diffraction (XRD). The magnetic property of the core-shell microspheres was investigated at room temperature. The results indicated that the core-shell composites had a well-retained high magnetic intensity, thus it can be easily separated from the mixture in less than a few minutes by simply using a magnet.

Optical and Magnetic Studies of Fe3O4/Au Core/Shell Nanocomposites

2019 ◽  
Vol 18 (05) ◽  
pp. 1850033 ◽  
Author(s):  
Al-Sayed A. M. Al-Sherbini ◽  
Gamal El-Ghannam ◽  
Hesham Yehya ◽  
O. Aied Nassef
Keyword(s):  
Shell Structures ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Visible Absorption ◽  
The Core ◽  
Transmission Electron ◽  
Surface Poisoning ◽  
Shell Particles

In this paper, we report the synthesis of Fe3O4 nanoparticles which are resistant to surface poisoning, has been adopted. Fe3O4 nanoparticles have been successfully coated with Au in the form of a shell with different sizes (Fe3O4/Au Core/Shell). Adjustment of the components’ ratio makes the shell thickness of the core/shell particles tunable. Thus, the presented route yields well-defined core/shell structures of different sizes in the range 15–57[Formula: see text]nm with varying the proportion of Au noble metal to Fe3O4 nanoparticles. The UV-Visible absorption spectra, X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) were applied for the characterization of the formed core/shell structures. Moreover, magnetic properties of the core/shell nanocomposites were also studied using Vibrating Sample Magnetometry (VSM).

Synthesis of Mixed TiO2-Rare Earth Up-Conversion Material and Application in the Dye-Sensitized Solar Cells

2013 ◽  
Vol 724-725 ◽  
pp. 89-92
Author(s):  
Fang Xue ◽  
Jun Zhang ◽  
Ya Han Wu ◽  
Xiu Fang Wang ◽  
Na Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Rare Earth ◽  
Dye Sensitized Solar Cells ◽  
Photoelectric Conversion Efficiency ◽  
Rare Earth Ion ◽  
Photoelectric Conversion ◽  
Dye Sensitized ◽  
Transmission Electron ◽  
Sensitized Solar Cells ◽  
Heterogeneous Layer

Rare earth ion-doped nanoparticles NaYF4:Yb3+,Ho3+ is one of the most efficient up-conversion nanosystems, when mixing a TiO2 heterogeneous layer outside can extends the range of NaYF4:Yb3+,Ho3+ nanoparticles absorb solar energy. In this work, a multi-functional mixed NaYF4:Yb3+,Ho3+-TiO2 structure was synthesized. The micromorphology, structure and particle size of the up-converting nanoparticles were characterized by transmission electron microscopy (TEM), and room temperature up-conversion luminescence (UCL) spectrofluorimetric measurements. The mixture of NaYF4:Yb3+,Ho3+ and TiO2 nanoparticles was applied to Dye-sensitized solar cells (DSSCs), the photoelectric conversion efficiency of the DSSC with up-conversion material is nearly twice as much as of the control DSSC irradiated by infrared (IR) light.

Synthesis and Annealing Effects on the Structure of Alumina by Polyol Mediated Process

2011 ◽  
Vol 691 ◽  
pp. 44-48
Author(s):  
M.A. Flores González ◽  
Maricela Villanueva-Ibáñez ◽  
M.A. Hernández-Pérez
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Emission Band ◽  
Emission Spectra ◽  
X Ray Diffraction ◽  
Rare Earth Ion ◽  
Reaction Route ◽  
Oxide Powders ◽  
Transmission Electron ◽  
Annealing Effects

Rare-earth ion (Eu3+ and Tb3+)-doped and undoped aluminum oxide powders have been prepared via polyol mediated synthesis. The precursors were aluminium nitrate, rare-earth (RE: Tb, Eu) nitrate and diethylene glycol. The powders were generated using low-temperature (Tmax ~ 200°C) and reaction time of 150 min. By controlling the acidity of the synthesis solution and the precursor concentration, sub-micrometric aggregates (about 300 nm) with spherical morphology were obtained. The powders of RE-doped Al2O3 were further investigated by photon correlation laser, X-ray diffraction, transmission electron microscope, scanning electron microscope, thermal analysis and photoluminescence emission spectra. The results showed that a-Al2O3 is formed at a temperature significantly lower than the solid sate reaction route. The luminescence of Al2O3 doped with 5 at.% Eu was observed with emission band in 614 nm and Al2O3 doped with 5 at.% Tb showed an emission band in 544 nm.

Sign in / Sign up

Export Citation Format

Share Document