scholarly journals Aiming to the superior of phosphor pattern: Influence of SiO2 nanoparticles on photoluminescence intensification of YAG:Ce

2021 ◽  
Vol 11 (6) ◽  
pp. 4833
Author(s):  
My Hanh Nguyen Thi ◽  
Thuc Minh Bui ◽  
Nguyen Doan Quoc Anh
Keyword(s):  
Yttrium Aluminum Garnet ◽  
Sol Gel ◽  
Micelle Formation ◽  
Sio2 Nanoparticles ◽  
Tem Analysis ◽  
Nano Composite ◽  
Light Emitting ◽  
X Ray ◽  
Wide Scale ◽  
Poly Ethylene

<span lang="EN-US">Yttrium aluminum garnet (YAG: RE) rare-earth-doped phosphors have great photoluminescence (PL) characteristics and are commonly used in light-emitting rectifying tubes. The RE elements used in these phosphors, however, are precious and in shortage. The production of phosphorus containing a limited amount of RE content is therefore essential. One solution is to manufacture Nano composite phosphors that use an inexpensive and more easily available content as a matrix for RE oxide. In this research, we developed a YAG: Ce/SiO2 Nano composite using a sol-gel procedure; in order to impulse micelle formation and agglomeration, poly (ethylene glycol) and urea have been added, respectively. X-ray diffraction, scanning and transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy were used to characterize the Nano composites. In proposing an explanation for this enhancement, we defined the concentration of SiO2 that produced optimum PL enhancement and used geometric models as well as the characterization consequences. Our results demonstrated that a 10% SiO2 concentration produced a 120% PL intensity of pure YAG:Ce. TEM analysis revealed that SiO2 nanoparticles filled the voids between the YAG:Ce crystals' single grain borders, hence inhibiting light scattering, resulting in increased PL. This procedure would be beneficial for the synthesis of low-RE and high-PL phosphors on a wide scale.</span>

Preparation of Al2O3/MgO Nano-Composite Particles for Bio-Applications

2020 ◽  
Vol 38 (4A) ◽  
pp. 586-593
Author(s):  
Hayder A. Sallal ◽  
Alla A. Abdul-Hameed ◽  
Farhad. M. Othman
Keyword(s):  
Composite Materials ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Composite Particles ◽  
X Ray Diffraction ◽  
Nano Composite ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This study describes the preparation and study of the properties of Nano composite particles prepared in a sol-gel method which consists of two materials (Αl2Ο3-MgΟ). The powder was evaluated by x-ray diffraction analysis, scanning electron microscopy analysis (SEM), particle size analysis, and energy dispersive x-ray analysis (EDX) and antibacterial test. The evaluation results of the nanocomposite particles shows a good distribution of the chemical composition between aluminum oxide and magnesium oxide, smoothness in particles  size where it reached to (54.9, 59.8) nm at calcination in (550 0C and 850 0C) respectively, formation of different shapes of nanoparticles and different  phases of the Αl2Ο3 particles (kappa and gamma) and nanopowder have well antibacterial action, Therefore, this reflects the efficiency of the proposed method to manufacture the nanocomposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications, especially in the fabrication of artificial limbs.

scholarly journals Effect of Additives on Characterization and Photocatalytic Activity of /ZnO Nanocomposite Prepared via Sol-Gel Process

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Shahram Moradi ◽  
Parviz Aberoomand Azar ◽  
Sanaz Raeis Farshid ◽  
Saeed Abedini Khorrami ◽  
Mohammad Hadi Givianrad
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Batch Reactor ◽  
Sol Gel ◽  
Methyl Cellulose ◽  
X Ray ◽  
Sol Gel Process ◽  
Poly Ethylene

TiO2/ZnO nanocomposites were prepared by the sol-gel method with and without addatives such as carboxy methyl cellulose (CMC), poly(ethylene glycol) (PEG), polyvinylpyrrolidon, (PVP), and hydroxylpropylcellulose (HPC). The characteristics of the prepared TiO2/ZnO nanocomposites were identified by IR spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) methods. The additives have a significant effect on the particle size distribution and photocatalytic activity of TiO2/ZnO nanocomposites. The photocatalytic activity of the synthesized nanocomposites was investigated for decolorization of methyl orange (MO) in water under UV-irradiation in a batch reactor and the results showed that the photocatalytic activity of the nanocomposites have been increased by CMC, PEG, PVP, and HPC, respectively. SEM has shown that the particle size distribution of TiO2/ZnO nanocomposite in the presence of HPC was better than the other samples.

PHOTO-CATALYTIC PROPERTIES OF TiO2–Fe2O3–La2O3 NANO-COMPOSITE FILMS

2009 ◽  
Vol 16 (02) ◽  
pp. 315-321 ◽  
Author(s):  
JING LI ◽  
MING-MING YAO ◽  
YING ZHANG ◽  
HUAI YANG
Keyword(s):  
Catalytic Properties ◽  
Energy Dispersive Spectrometer ◽  
Sol Gel ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Photo Degradation ◽  
Nano Composite ◽  
Nano Structure ◽  
X Ray ◽  
Co Doped

Titanium dioxide doped Fe 3+ and La 3+ nano-composite films were prepared using the sol–gel method. The photo-catalytic properties were evaluated by photo-degradation of methyl orange in solution. Scanning electron microscope, X-ray diffraction, and energy dispersive spectrometer were used to characterize the TiO 2 film doped Fe 3+ and La 3+, indicating that the film has nano-structure, and mainly anatase crystal. It is proved that co-doped Fe 3+ and La 3+ can improve significantly the photo-catalytic properties of TiO 2 film due to the synergistic effect of the two ions.

Photoluminescence Properties of Eu2+,Mn 2+Co-Doped Ca10Si6O21Cl2 by Sol–Gel Method

2011 ◽  
Vol 239-242 ◽  
pp. 2124-2127 ◽  
Author(s):  
Yong Sheng Shi ◽  
Hui Rong Zhao ◽  
Bang Qing Wang ◽  
Su Hang Gu
Keyword(s):  
Emission Spectrum ◽  
White Light ◽  
Sol Gel ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Reductive Atmosphere ◽  
Co Doped ◽  
The Ideal

White light-emitting materials of Eu2+, Mn2+-codoped Ca2SiO3Cl2were prepared. Luminescence properties and other samples phase were tested by X-ray diffraction (XRD) and fluorescence spectrophotometer (PL). The results showed that the temperature range of 730°C to 760°Cand the ideal holding time is 4h~5h, the emission spectrum of Eu2+-doped sample under excitation at 365nm wavelength was 426nm, 524nm in a weak reductive atmosphere of active carbon, the emission spectrum of Eu2+, Mn2+co-doped samples was 426nm, 524nm, 585nm, the three combined can produce white light.

scholarly journals Preparation of AgI/Silica/Poly(Ethylene Glycol) Nanoparticle Colloid Solution and X-Ray Imaging Using It

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Yoshio Kobayashi ◽  
Tetsuya Ayame ◽  
Tomohiko Nakagawa ◽  
Yohsuke Kubota ◽  
Kohsuke Gonda ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Sol Gel ◽  
Particle Surface ◽  
Iodine Concentration ◽  
Colloid Solution ◽  
Poly Ethylene Glycol ◽  
X Ray ◽  
X Ray Imaging ◽  
Poly Ethylene ◽  
Surface Modified

This work performed X-ray imaging of mouse by using aqueous colloid solution of AgI nanoparticles coated with silica (AgI/SiO2) and then surface-modified with poly(ethylene glycol) (PEG) (AgI/SiO2/PEG). A colloid solution of AgI nanoparticles was prepared by mixing silver perchlorate and potassium iodide in water. The AgI nanoparticles were surface-modified with 3-mercaptopropyltrimethoxysilane and then were silica-coated by a sol-gel reaction between tetraethylorthosilicate and H2O catalyzed with NaOH in ethanol. The AgI/SiO2 particle surface was modified with PEG by using methoxy PEG silane CH3OCH2CH2OnCH2CONHC3H6SiOC2H53. The AgI/SiO2/PEG colloid solution revealed a computed tomography value as high as 1343.6 HU at an iodine concentration of 0.1 M, which was higher than a commercial X-ray contrast agent with the same iodine concentration. Tissues of mouse could be imaged by injecting the concentrated colloid solution into them.

Synthesis and Characterization of ZnS:Mn2+ Nano-Particles for White-Light Emitting

2008 ◽  
Vol 8 (3) ◽  
pp. 1199-1202 ◽  
Author(s):  
Li Qing Yue ◽  
Fu Jun Zhang ◽  
Jin Zhao Huang ◽  
Li Wei Wang
Keyword(s):  
Methacrylic Acid ◽  
White Light ◽  
Sol Gel ◽  
Average Particle Size ◽  
Nano Particles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zinc Blend ◽  
Light Emitting ◽  
X Ray

The sol–gel method was used to obtain a kind of white-light emitting ZnS:Mn2+ nanoparticles capped by methacrylic acid with an average particle size of ∼7nm. The photoluminescence spectra, X-ray diffraction spectra, Fourier transform infrared reflection spectra and ultraviolet absorption spectra were used to measure their optical properties and crystal structures. The ZnS:Mn2+ nanoparticles with 0.58 wt% Mn2+ concentration emitted white light when excited by 380 nm. The PL spectrum exhibits two emission peaks under irradiation: one at 480 nm generated from the ZnS matrix, and one at 590 nm emitted by the doped Mn2+ ions. The nanoparticles will only emit white light with the optimum Mn2+ concentration (0.58 wt%). X-ray diffraction demonstrates the synthesized ZnS:Mn2+ nanoparticles have zinc blend crystal structure, and the infrared patterns of the capped ZnS:Mn2+ nanoparticles and methacrylic acid are comparable, indicating that the methacrylic polymer has capped or modified ZnS:Mn2+ nanoparticles.

Lead Zirconate Nanotubes: Synthesis, Structural Characterization and Growth Mechanism

2008 ◽  
Vol 8 (11) ◽  
pp. 5757-5761 ◽  
Author(s):  
Satyendra Singh ◽  
S. B. Krupanidhi
Keyword(s):  
Electron Microscope ◽  
Structural Characterization ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Tem Analysis ◽  
X Ray ◽  
Sem Image ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem

This paper reports an experimental study on the synthesis and structural characterization of lead zirconate, PbZrO3, (PZ) nanotubes fabricated by an improved sol–gel method within the nanochannels of anodic aluminum oxide (AAO) templates. The morphology, structure, and composition of the nanotubes were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected-area electron diffraction (SAED), high resolution TEM (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). The results of XRD and SAED indicated that postannealed (700 °C for 1 h) PZ nanotubes had an orthorhombic distorted perovskite polycrystalline crystal. SEM and TEM analysis revealed that PZ nanotubes possessed a uniform length and diameter, which were controlled by the thickness and the pore diameter of the applied AAO template, respectively and the thickness of the wall of the PZ nanotubes was about 15 nm. Y-junctions were also observed in the PZ nanotubes. EDX analysis demonstrated that stoichiometric PbZrO3 was formed. HRTEM image and a typical SEM image confirmed that the obtained PZ nanotubes composed of nanoparticles in the range of 4–8 nm. The possible formation mechanism of nanotubes was discussed.

scholarly journals Characterization of Enhanced Antibacterial Effects of Silver Loaded Cerium Oxide Catalyst

2018 ◽  
Vol 34 (6) ◽  
pp. 2895-2901
Author(s):  
Gusliani Eka Putri ◽  
Syukri Arief ◽  
Novesar Jamarun ◽  
Feni Rahayu Gusti ◽  
Annisa Novita Sary
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sol Gel ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference

Silver-cerium nanoparticles had been successfully synthesized using the sol-gel method by silver nitrate as a source of silver and cerium nitrate hexahydrate as a source of cerium. The synthesized silver-cerium nanoparticles had been characterized by X-ray diffraction,transmission electron microscopy, and scanning electron microscopy-energy dispersive X-ray. Based on the results of XRD and TEM analysis showed silver-cerium nanoparticles were spherical with the dominant size range of 8.9 -12.73 nm. SEM-EDX analysis showed silver nanoparticles covered by cerium nanoparticles that were known as the core-shell structure. Silver nanoparticles doped with cerium nanoparticles (CeONP) showed an increase in inhibitory with an increase a zone of inhibition after being doped with cerium nanoparticles. The disinfection effect of Ag-doped CeONP was more pronounced on Staphylococcus aureus than Escherichia coli, although the difference was not wide.

Microstructure and optical properties of Na-doped ZnO system, synthesized by the sol–gel method

2019 ◽  
Vol 97 (4) ◽  
pp. 254-258 ◽  
Author(s):  
Fan Tong ◽  
Ye Zhao ◽  
Mao-Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Lattice Structure ◽  
Sol Gel ◽  
Average Crystalline Size ◽  
Tem Analysis ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Pure and Na-doped ZnO (2 at.%, 5 at.%, and 10 at.%) films are synthesized by sol–gel method and annealed at 500 °C for 4 h. The as-synthesized nanoparticles are characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS). The samples exhibited hexagonal ZnO lattice structure and another Na2O2 phase was detected in the 5 at.% Na-doped ZnO sample. The calculated average crystalline size increases from 42.0 nm to 43.5 nm when Na content increased from 0 to 10 at.%. FESEM and TEM analysis identifies that the average size of the Na-doped ZnO nanoparticles lies in between 50 nm and they appear in spheroid-like or rod-like shaped particles. The transmittance of the sample was above 80% and the results of photocatalytic activity show that Na-doped ZnO nanoparticles exhibit higher photodegradation activity (about 91%) than pure ZnO nanoparticles under UV irradiation.

Study on the Dispersion of Nanometer TiO2 Powder by Sol-Gel Method

2012 ◽  
Vol 599 ◽  
pp. 104-107
Author(s):  
Fang Zhao ◽  
Ya Qiong Zhao ◽  
Yuan Yuan Li ◽  
Gang Ni
Keyword(s):  
Photocatalytic Activity ◽  
Nonionic Surfactants ◽  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron

This study investigated the effect of cationic, anionic, and nonionic surfactants on the formation, morphology, and surface properties of TiO2 nanoparticles synthesized by modified sol-gel method. The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD results showed TiO2 nanoparticles synthesized with different surfactants only include anatase phase. The TEM analysis revealed the surfactants can enhance dispersion of TiO2 nanoparticles. In contrast, the anionic surfactants showed hightly effects. The photocatalytic activity of samples was tested for degradation of methyl orange (MO) solutions. The results showed photocatalytic activity of the catalyst with surfactants was higher than pure TiO2 under ultraviolet.

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