scholarly journals Solvothermal Synthesis ofGd2O3 : Eu3+Luminescent Nanowires

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Guixia Liu ◽  
Song Zhang ◽  
Xiangting Dong ◽  
Jinxian Wang
Keyword(s):  
Large Scale ◽  
Hexagonal Phase ◽  
Infrared Spectrometry ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Display Devices ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Facile Solvothermal Method ◽  
Better Than

UniformGd2O3 : Eu3+luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000) as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD) patterns and Fourier transform infrared spectrometry (FTIR) showed that the precursors are hexagonal phaseGd(OH)3crystals, and the samples calcined at 800C°are cubic phaseGd2O3. Transmission Electron Microscopy (TEM) images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL) spectra showed that the ratio ofD50→F72toD50→F71transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of theGd2O3 : Eu3+is better than that of the precursors. The as-obtainedGd2O3 : Eu3+luminescent nanowires show a strong red emission corresponding toD50→F72transition (610 nm) ofEu3+under ultraviolet excitation (250 nm), which have potential application in red-emitting phosphors and field emission display devices.

Study on Modified Rapeseed Oil/Montmorillonite Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 1291-1294 ◽  
Author(s):  
Bin Lü ◽  
Jian Zhong Ma ◽  
Dang Ge Gao ◽  
Lei Hong
Keyword(s):  
Rapeseed Oil ◽  
Fourier Transforms ◽  
Raw Materials ◽  
Infrared Spectrometry ◽  
Emulsifying Properties ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Better Than

Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.

scholarly journals Photosensitization of TiO2 P25 with CdS Nanoparticles for Photocatalytic Applications

2017 ◽  
Vol 62 (2) ◽  
pp. 841-849 ◽  
Author(s):  
A. Trenczek-Zając ◽  
J. Banaś ◽  
K. Świerczek ◽  
K. Zazakowny ◽  
M. Radecka
Keyword(s):  
Molar Fraction ◽  
Fundamental Absorption Edge ◽  
Coupled System ◽  
Precipitation Method ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Means Of Transmission ◽  
Better Than

AbstractA TiO2/CdS coupled system was prepared by mixing the TiO2P25 with CdS synthesized by means of the precipitation method. It was found that the specific surface area (SSA) of both components is extremely different and equals 49.5 for TiO2and 145.4 m2·g−1for CdS. The comparison of particle size distribution and images obtained by means of transmission electron microscopy (TEM) showed agglomeration of nanocomposites. X-ray diffraction (XRD) patterns suggest that CdS crystallizes in a mixture of cubic and hexagonal phases. Optical reflectance spectra revealed a gradual shift of the fundamental absorption edge towards longer wavelengths with increasing CdS molar fraction, which indicates an extension of the absorption spectrum of TiO2. The photocatalytic activity in UV and UV-vis was tested with the use of methyl orange (MO). The Langmuir–Hinshelwood model described well the photodegradation process of MO. The results showed that the photocatalytic behaviour of the TiO2/CdS mixture is significantly better than that of pure nanopowders.

scholarly journals Synthesis and Characterization of Cysteine-Capped CdSe Nanoparticles Using an Alternative of Selenium

2019 ◽  
Vol 31 (11) ◽  
pp. 2457-2460
Author(s):  
K.E. Mokubung ◽  
M.J. Moloto ◽  
K.P. Mubiayi ◽  
N. Moloto
Keyword(s):  
Cdse Nanoparticles ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Prepared Nanoparticles ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Average Size

Present work reports synthesis of L-cysteine capped CdSe nanoparticles at different temperatures via an aqueous medium, non-toxic and green colloidal route. Cadmium chloride (CdCl2·5H2O) and sodium selenite (Na2SeO3) were used as cadmium and selenium sources respectively. The prepared nanoparticles are characterized by UV-visible absorption and photoluminescence spectroscopy, Fourier transform infrared, X-ray diffraction and transmission electron microscopy. The XRD patterns confirm a cubic phase structure of the prepared nanoparticles at 55, 75 and 95 ºC, respectively. The TEM analysis, optical absorption and photoluminescence spectra shows epitaxial growth of CdSe nanoparticles as the temperature increases with average size diameter of 4.12 ± 0.32, 5.02 ± 0.234 and 5.53 ± 0.321 nm for 55, 75 and 95 ºC, respectively.

Effect of Hydrothermal Treatment on Structural Character of Palygorskite and Adsorption Efficiency for Methylene Blue

2013 ◽  
Vol 726-731 ◽  
pp. 560-564 ◽  
Author(s):  
Xue Ping Wu ◽  
Cun Liu ◽  
Liang Zhang ◽  
Xian Long Zhang ◽  
Li Ping Cheng
Keyword(s):  
Methylene Blue ◽  
Hydrothermal Treatment ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Structural Character ◽  
Transmission Electron ◽  
Bet Specific Surface Area ◽  
Bet Analysis ◽  
Xrd Patterns

Palygorskite is widely used as an adsorbent for all kinds of pollutants in wastewater. The effect of hydrothermal treatment parameters including temperature and time on palygorskite's structural character and its adsorption of methylene blue were studied. The structures of the prepared palygorskite adsorbent were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (IR), and Brunauer-Emmett-Teller (BET) analysis. The results illustrate that the palygorskite fibers become shorter evidenced by TEM analysis, but there is no obvious destruction of crystal structure in XRD patterns. The BET specific surface area of palygorskite gets the largest after hydrothermal treatment at 110 °C, and then gradually reduces. Correspondingly, the adsorption capacity of methylene blue (MB) on palygorskite increases at 110 °C and then decreases till 250 °C.

Synthesis of Lanthanide-Ion-Doped NaYF4 RGB Up-Conversion Nanoparticles for Anti-Counterfeiting Application

2018 ◽  
Vol 18 (12) ◽  
pp. 8207-8215 ◽  
Author(s):  
Guo Gong ◽  
Shaowen Xie ◽  
Ya Song ◽  
Haihu Tan ◽  
Jianxiong Xu ◽  
...  
Keyword(s):  
Hexagonal Phase ◽  
Lanthanide Ions ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
Lanthanide Ion ◽  
Molar Ratios ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Luminescent Polymer ◽  
Luminescent Ink

Well-defined and mono-dispersed lanthanide-ion-doped NaYF4 up-conversion nanoparticles (UCNPs) were synthesized via thermal decomposition using lanthanide oleate as the precursor. By rational selecting the dopant pairs of the doped lanthanide ions (Y3+, Yb3+, Er3+ and Tm3+) with accurate molar ratios, three-primary-color (RGB) UCNPs which exhibited green (UCNPs-G), blue (UCNPs-B) and red (UCNPs-R) fluorescence, respectively, were prepared. The X-ray diffraction (XRD) patterns showed that the three UCNPs were purely hexagonal-phase NaYF4 crystals. Transmission electron microscopy (TEM) images revealed that the synthesized UCNPs exhibited well-defined nanosphere morphology with uniform size distribution. The average diameters were 23.95±3.35 nm for UCNPs-G, 20.63±2.59 nm for UCNPs-B, and 19.24±2.37 nm for UCNPs-R, respectively. After surface modification employing polyacrylic acid (PAA) as modifier, the obtained UCNPs were converted to be hydrophilic, which can be used as fillers to construct luminescent polymer films and luminescent ink in anti-counterfeiting application.

High quality GdSil.7 layers formed by high dose channeled implantation

1996 ◽  
Vol 427 ◽  
Author(s):  
M. F. Wu ◽  
A. Vantomme ◽  
H. Pattyn ◽  
G. Langouche ◽  
H. Bender
Keyword(s):  
Ion Beam ◽  
Hexagonal Phase ◽  
Hexagonal Structure ◽  
High Dose ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Silicide Layer ◽  
Transmission Electron ◽  
Better Than

AbstractThin gadolinium silicide layers have been formed by channeled ion beam synthesis. Continuous and heteroepitaxial GdSil.7 layers with a hexagonal structure and a χmin value of 10% are prepared by Gd ion implantation at 90 keV to a dose of 1.3x1017/cm2 at 450°C in Si(111) using channeled implantation. The hexagonal phase of GdSi1.7 is stable up to a temperature of 850°C. Both the crystalline quality and the phase stability are much better than the results obtained by conventional techniques. Annealing at > 900°C suddenly changes the χmin value of the silicide layer from 10% to 100%. X-ray diffraction shows that the phase has changed to orthorhombic. RBS/channeling, x-ray diffraction and transmission electron microscopy are used in this study.

scholarly journals Effect of anions on the structural, morphological and dielectric properties of hydrothermally synthesized hydroxyapatite nanoparticles

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Lakshmanaperumal Sundarabharathi ◽  
Deepalekshmi Ponnamma ◽  
Hemalatha Parangusan ◽  
Mahendran Chinnaswamy ◽  
Mariam Al Ali Al-Maadeed
Keyword(s):  
Electron Microscopy ◽  
Dielectric Properties ◽  
Hexagonal Phase ◽  
Biological Properties ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Polarized Surface ◽  
Egg Shell ◽  
Xrd Patterns ◽  
Source Materials

Abstract Synthetic nano hydroxyapatites (HA) have been considered as potential biomaterials for bone tissue engineering applications because of its excellent biological properties. The present work deals with the synthesis of HA nanoparticles from different anion source materials via autoclave assisted hydrothermal method. All the prepared HA nanoparticles were characterized by X-ray diffraction (XRD), Fourier transformation infrared spectra, field emission scanning electron microscopy, energy dispersive spectra and high resolution transmission electron microscopy. The XRD patterns reveal the pure and hexagonal phase structure with smaller crystallite size for HA obtained from various calcium salt precursors. HA particles prepared from nitrate precursors show spherical morphology with 32 nm grain size whereas those derived from the acetate, chloride and egg shell precursors respectively show needle-like, irregular and oval morphology. The effect of different anions on the dielectric properties and alternating conductivity of HA is investigated, as a polarized surface can trigger biological reactions. For the particles obtained from nitrate, acetate, chloride and egg shell precursors respectively give dielectric constant (εʹ) values of 9.96, 13.22, 9.92 and 10.86 at 5 MHz. The εʹ and dielectric loss (εʹʹ) values for the HA nanoparticles decrease with increase in the applied frequency as well. The alternating current conductivity values confirm that the as-synthesized HA samples exhibit insulating behavior. In short this article provides the various applicability of HA particles in optoelectronics and drug delivery. Graphic abstract

Low Temperature Large Scale CVD Synthesis of Nano Onion-Like Fullerenes

2012 ◽  
Vol 490-495 ◽  
pp. 3211-3214 ◽  
Author(s):  
Lei Shan Chen ◽  
Cun Jing Wang
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Aluminum Hydroxide ◽  
Large Scale ◽  
Iron Catalyst ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Naoh Solution ◽  
Synthesis Reactions

Synthesis reactions were carried out by chemical vapor deposition using iron catalyst supported on aluminum hydroxide at 400 °C and 420 °C, in the presence of argon as carrier gas and acetylene as carbon source. The aluminum hydroxide support was separated by refluxing the samples in 40% NaOH solution for 2 h and 36% HCl solution for 24 h, respectively. The samples were characterized by field-emission scanning electron microscopy, energy dispersive spectroscopy, high-resolution transmission electron microscopy and X-ray diffraction. The results show that carbon nanotubes were the main products at 420 °C, while large scale high purity nano onion-like fullerenes encapsulating Fe3C, with almost uniform sizes ranging from 10-50 nm, were obtained at the low temperature of 400 °C.

Microstructure Characterization of Metal Mixed Oxides

MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko
Keyword(s):  
Mixed Oxides ◽  
Profile Analysis ◽  
Atomic Resolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Reconstruction Procedure ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Co Precipitation

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.

The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

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