Growth and Optical Properties of SnO2 Ultra-Small Nanorods by the Novel Micelle Techniques

2008 ◽  
Vol 1087 ◽  
Author(s):  
Satchidananda Rath ◽  
Shinji Nozaki ◽  
Hiroshi Ono ◽  
Kazuo Uchida ◽  
Satoshi Khojima
Keyword(s):  
Quantum Confinement ◽  
Photoluminescence Spectrum ◽  
Tin Dioxide ◽  
Optical Band Gap ◽  
Quantum Confinement Effect ◽  
Average Diameter ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

AbstractTin-dioxide (SnO2) ultra-small nanorods (UNR) have been successfully synthesized using the novel micellar technique. From transmission electron microscopy, the average diameter and length of the UNRs are estimated to be 1.3 nm and 5.0 nm, respectively. The crystal structure of the SnO2 UNRs was found to be tetragonal from the glazing incidence x-ray diffraction. The optical band gap estimated from the absorption spectrum is blue-shifted by 1 eV from that of bulk (3.64 eV). The photoluminescence spectrum shows two groups of peaks each with several fine peaks, one in the wavelength range of 270 – 370 nm and the other in the range of 380 – 500 nm which are due to the strong quantum confinement effect.

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

Sb-rich nanoinclusions in an AlGaAsSb metamaterial

MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 277-284
Author(s):  
Nikolay A. Bert ◽  
Vladimir V. Chaldyshev ◽  
Nikolay A. Cherkashin ◽  
Vladimir N. Nevedomskiy ◽  
Valery V. Preobrazhenskii ◽  
...  
Keyword(s):  
Molecular Beam ◽  
Filling Factor ◽  
Local Thermodynamic Equilibrium ◽  
Average Diameter ◽  
Formation Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Self Organized ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTWe studied the microstructure of Al0.28Ga0.72As0.972Sb0.028 metamaterials containing a developed array of AsSb nanoinclusions. The AlGaAsSb films were grown by low-temperature molecular-beam epitaxy followed by high-temperature annealing at 750°C. The process resulted in an array of self-organized AsSb nanonclusions with an average diameter of 15 nm. The volume filling factor was about 0.003. Using transmission electron microscopy and x-ray diffraction we showed that the nanoinclusions have A7-type rhombohedral atomic structure with the following orientation in the matrix (0003)p || {111}m and [-2110]p || 〈220〉m, where p and m indices indicate the AsSb precipitate and AlGaAsSb matrix, correspondingly. The nanoinclusions appeared to be strongly enriched by antimony (more than 90 atomic %), whereas the Sb content in the AlGaAsSb matrix was 2.8 atomic %. The strong enrichment of the inclusion with Sb resulted from the local thermodynamic equilibrium between the solid AlGaAsSb matrix and AsSb inclusions which became liquid at a formation temperature of 750°C.

scholarly journals Luminescence Studies and Judd–Ofelt Analysis on SiO2@LaPO4:Eu@SiO2 Submicro-spheres with Different Size of Intermediate Shells

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiaowei Zhu ◽  
Kuisuo Yang ◽  
Anping Wu ◽  
He Bai ◽  
Jinrong Bao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Optical Transition ◽  
Dipole Transition ◽  
Rare Earth Ions ◽  
Photoluminescence Intensity ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Abstract The novel submicro-spheres SiO2@LaPO4:Eu@SiO2 with core-shell-shell structures were prepared by connecting the SiO2 submicro-spheres and the rare earth ions through an organosilane HOOCC6H4N(CONH(CH2)3Si(OCH2CH3)3 (MABA-Si). The as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR). It is found that the intermediate shell of the submicro-spheres was composed by LaPO4:Eu nanoparticles with the size of about 4, 5–7, or 15–34 nm. A possible formation mechanism for the SiO2@LaPO4:Eu@SiO2 submicro-spheres has been proposed. The dependence of the photoluminescence intensity on the size of the LaPO4:Eu nanoparticles has been investigated. The intensity ratios of electrical dipole transition 5D0 → 7F2 to magnetic dipole transition 5D0 → 7F1 of Eu3+ ions were increased with decreasing the size of LaPO4:Eu nanoparticles. According to the Judd-Ofelt (J-O) theory, when the size of LaPO4:Eu nanoparticles was about 4, 5–7 and 15–34 nm, the calculated J-O parameter Ω2 (optical transition intensity parameter) was 2.30 × 10−20, 1.80 × 10−20 and 1.20 × 10−20, respectively. The increase of Ω2 indicates that the symmetry of Eu3+ in the LaPO4 lattice was gradually reduced. The photoluminescence intensity of the SiO2@LaPO4:Eu@SiO2 submicro-spheres was unquenched in aqueous solution even after 15 days.

Laccase Biosensor Based on Ag-Doped TiO2 Nanoparticles on CuCNFs for the Determination of Hydroquinone

NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650132 ◽  
Author(s):  
Jie Yang ◽  
Dawei Li ◽  
Zengyuan Pang ◽  
Qufu Wei
Keyword(s):  
Electron Microscopy ◽  
Storage Stability ◽  
Electrochemical Impedance ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
New Material ◽  
And Storage

A novel nanomaterial composed of copper and carbon nanofibers (CuCNFs) decorated with Ag-doped TiO2 (Ag–TiO[Formula: see text] nanoparticles was prepared through electrospinning, carbonization and solvothermal treatment. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The obtained composites were mixed with laccase and Nafion to construct novel hydroquinone biosensor. The electrochemical behavior of the novel biosensor was studied using cyclic voltammetry (CV) and chronoamperometry. The results demonstrated that the biosensor possessed a wide detection linear range (1.20–176.50[Formula: see text][Formula: see text]M), a good selectivity, repeatability, reproducibility and storage stability. This work provides a new material to design more efficient laccase (Lac) based biosensor for hydroquinone detection.

Synthesis and upconversion luminescence properties of CaF2:Yb3+,Er3+ nanoparticles obtained from SBA-15 template

2010 ◽  
Vol 25 (10) ◽  
pp. 2035-2041 ◽  
Author(s):  
Zhiguo Xia ◽  
Peng Du
Keyword(s):  
Electron Microscopy ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Average Diameter ◽  
Cubic Phase ◽  
Pumping Power ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Transmission Electron

CaF2:Yb3+,Er3+ upconversion (UC) luminescence nanoparticles have been synthesized using mesoporous silica (SBA-15) as a hard template. The samples were characterized by x-ray diffraction, Fourier transform infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy, and UC emission spectra, respectively. Highly crystalline cubic phase CaF2:Yb3+,Er3+ nanoparticles are uniformly distributed with an average diameter of about 40–50 nm, and the formation process is also demonstrated. The UC fluorescence has been realized in the as-prepared CaF2:Yb3+,Er3+ nanoparticles on 980-nm excitation. The UC emission transitions for 4F9/2–4I15/2 (red), 2H11/2–4I15/2 (green), 4S3/2–4I15/2 (green), and 2H9/2–4I15/2 (violet) in the Yb3+/Er3+ codoped CaF2 nanoparticles depending on pumping power and temperature have been discussed. The UC mechanism, especially the origin on the temperature-dependent UC emission intensities ratio between 2H11/2 and 4S3/2 levels, have been proposed.

Fabrication of boron carbonitride (BCN) nanotubes and giant fullerene cages

2010 ◽  
Vol 88 (12) ◽  
pp. 1256-1261 ◽  
Author(s):  
Guifang Sun ◽  
Faming Gao ◽  
Li Hou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
The Novel ◽  
X Ray Diffraction ◽  
Boron Carbonitride ◽  
X Ray ◽  
Transmission Electron ◽  
New Form ◽  
First Time ◽  
Electron Energy Loss

Boron carbonitride (BCN) nanotubes have been successfully prepared using NH4Cl, KBH4, and ZnBr2 as the reactants at 480 °C for 12 h by a new benzene-thermal approach in a N2 atmosphere. As its by-product, a new form of carbon regular hexagonal nanocages are observed. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), transmission electron diffraction (TED), electron energy loss spectroscopy (EELS), and high-resolution transmission electron microscopy (HRTEM). The prepared nanotubes have uniform outer diameters in the range of 150 to 500 nm and a length of up to several micrometerss. The novel carbon hexagonal nanocages have a typical size ranging from 100 nm to 1.5 µm, which could be the giant fullerene cages of [Formula: see text] (N = 17∼148). So, high fullerenes are observed for the first time. The influences of reaction temperature and ZnBr2 on products and the formation mechanism of BCN nanotubes are discussed.

An environmentally friendly method for the isolation of cellulose nano fibrils from banana rachis fibers

2016 ◽  
Vol 87 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vincent Mukwaya ◽  
Weidong Yu ◽  
Rabie AM Asad ◽  
Hajo Yagoub
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Enzyme Hydrolysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sonic Treatment ◽  
Xrd Studies ◽  
Environmentally Friendly Method ◽  
Derivative Thermogravimetry

Cellulose nano fibrils (CNFs) were isolated from banana rachis bran using enzyme hydrolysis with subsequent ultra-sonic treatment. The CNFs and bran were characterized by particle size distribution (only the CNFs), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy; the morphology of the banana rachis fiber and CNFs was observed using scanning electron microscopy and transmission electron microscopy, respectively. The furnished nano fibrils had an average diameter of 14.02 ± 2.10 nm and length of 619.6 ± 90.7 nm. The aspect ratio of the CNFs is in the range of long fibrils, that is 44.18. XRD studies revealed that CNFs (48.83%) were more crystalline than the banana bran (27.76%). TGA and derivative thermogravimetry thermograms showed that CNFs were more thermally stable than the bran.

scholarly journals FePt3 nanosuspension synthesized from different precursors – a morphological comparison by SAXS, DLS and TEM

2017 ◽  
Vol 65 (1) ◽  
pp. 79-84
Author(s):  
P. Sarmphim ◽  
S. Soontaranon ◽  
C. Sirisathitkul ◽  
P. Harding ◽  
S. Kijamnajsuk ◽  
...  
Keyword(s):  
Data Storage ◽  
Biomedical Applications ◽  
Average Diameter ◽  
The Other ◽  
X Ray Diffraction ◽  
Morphological Comparison ◽  
X Ray ◽  
Iron Platinum ◽  
X Ray Scattering ◽  
Transmission Electron

Abstract Annealed iron-platinum (FePt) is ferromagnetic in a nanoscale regime which is necessary for energy and data storage, whereas the as-synthesized form of FePt-based nanoparticles exhibits superparamagnetism useful for biomedical applications. In this study, as-synthesized nanosuspensions from the reaction of Pt(acac)2 with Fe(acac)3 and Fe(hfac)3 are compared. X-ray diffraction (XRD) peaks for both samples are assigned to the FePt3 phase. As shown by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS), nanoparticles synthesized by using Fe(acac)3 have a smaller average diameter, but larger polydispersity index and particle agglomerations. On the other hand, the nanoparticles synthesized by using Fe(hfac)3 can self-assemble into a longer range of patterned monolayer. Dynamic light scattering (DLS), measuring the size of cluster of nanoparticles as well as oleic acid and oleylamine at their surface, confirms that larger agglomerations in the sample were synthesized by using Fe(acac)3. In addition to the size distribution, magnetic properties were influenced by the composition of these nanoparticles.

scholarly journals Новые гетерогенные наноструктурные катализаторы на основе наночастиц переходных металлов и гексагонального нитрида бора

2021 ◽  
Vol 47 (16) ◽  
pp. 10
Author(s):  
А.С. Конопацкий ◽  
К.Л. Фаерштейн ◽  
И.Н. Волков ◽  
Д.В. Лейбо ◽  
В.В. Калинина ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Thermal Activation ◽  
Fept Nanoparticles ◽  
The Novel ◽  
Surface Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Conversion

Structure and catalytic activity of the novel heterostructured FePt/h-BN nanomaterials in carbon monoxide oxidation reaction were studied. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction methods were used for structure and surface chemical composition investigation. Developed materials were demonstrated to have enhanced catalytic activity with 100% CO conversion at 250 °C. Structure ordering in FePt nanoparticles was observed during thermal activation of the material.

scholarly journals S tudies on the phase transitions and properties of tungsten (VI) oxide nanoparticles by X - Ray diffraction (XRD) and thermal analysis

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
S.F. Abdullah ◽  
S. Radiman ◽  
M.A. Abdul Hamid ◽  
N.B. Ibrahim
Keyword(s):  
Thermal Analysis ◽  
Phase Transitions ◽  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Scherrer Formula

Tungsten (VI) oxide, WO3nanoparticles were synthesized by colloidal gas aphrons(CGAs) technique.The resultant WO3nanoparticleswere characterized by thermogravimetric-differential thermal analysis (TG-DTA) and X-Ray diffraction (XRD) measurements in order to determine the phase transitions, the crystallinity and the size of theWO3nanoparticles. As a comparison, transmission electron microscope (TEM) was used to investigate the size of the WO3nanoparticles. The result from XRD and DTA show that the formation of polymorphsWO3nanoparticles have the following sequence: orthorhombic (b-WO3)®monoclinic (g-WO3) ®triclinic (d-WO3) ®monoclinic (e-WO3) with respect to the calcination temperature of 400, 500, 600 and 700°C. No diffraction peaks were found in the X-Ray diffraction measurements for the sample heat treated at 300°C (as-prepared), suggesting that an amorphous structure was obtained at this temperature whereas the crystallinity had been obtained by the other samples of theWO3nanoparticles at the calcination temperatures of 400, 500, 600 and 700°C. It is also found that the X-Ray diffraction measurements produced an average diameter of (30 ±5), (50 ±5), (150 ±10) and (200 ±10) nm at calcination temperatures of 400, 500, 600 and 700°C respectively by using Debye-Scherrer formula. The TG curve revealed that the WO3nanoparticles is purely anhydrous since the weight loss is insignificant (0.3 –1.4) % from 30 until 600°C for the WO3nanoparticles calcined at 400°C. Finally, the composition and the purity of the WO3nanoparticleshave been examined by X-Ray photoelectron spectroscopy (XPS). Theresults indicate no significant changes to the composition and the purity of the WO3nanoparticle produced due to the temperature variations 

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