A New Hydrothermal Route for Synthesis of Molybdenum Disulphide Nanorods and Related Nanostructures

2006 ◽  
Vol 6 (1) ◽  
pp. 168-174 ◽  
Author(s):  
Jyoti R. Ota ◽  
Suneel K. Srivastava
Keyword(s):  
Nitrogen Atmosphere ◽  
Simple Approach ◽  
Photoluminescence Spectra ◽  
Energy Dispersive Analysis ◽  
X Ray Diffraction ◽  
Molybdenum Disulphide ◽  
Hydrothermal Route ◽  
X Ray ◽  
20 Nm ◽  
Thermally Treated

A simple approach to prepare nanorods of Molybdenum Disulphide (MoS2) using hydrothermal method by reacting aqueous solutions of (NH4)6Mo7O24 · 4 H2O, C2H4NS and Na2S2O4 at 190 °C for 24 h is described. The hydrothermal product has been subsequently subjected to the thermal treatment in nitrogen atmosphere at 675 °C for 6 h and characterized. X-ray diffraction (XRD) of the hydrothermal product indicated the formation of MoS2 relatively with much lower crystallinity compared to when it thermally treated. Energy dispersive analysis (EDX) was done to know the chemical composition of the product. TEM showed onset growth of MoS2 nanorods within the hydrothermal products itself and in thermally treated products it was prominent with the diameter of the nanorods ranging between 10–20 nm. Photoluminescence spectra MoS2 nanorods shows an intense absorbance at around 429 nm. TGA of the MoS2 nanorods in air and nitrogen atmosphere has also been studied. The extent of formation of MoS2 from the precursors obtained at 190 °C for duration of 12, 18, and 24 h and annealed at 675 °C for 6 h under nitrogen atmosphere is also demonstrated based on XRD data.

Formation and characteristics of nanocrystalline composites γ–TiAl + Ti2AlN by mechanical alloying and subsequent annealing treatment

1995 ◽  
Vol 10 (5) ◽  
pp. 1247-1255 ◽  
Author(s):  
K.Y. Wang ◽  
J.G. Wang ◽  
G.L. Chen
Keyword(s):  
Amorphous Phase ◽  
Annealing Treatment ◽  
Nitrogen Atmosphere ◽  
Subsequent Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanocrystalline Composites ◽  
Transmission Electron ◽  
Different Temperatures ◽  
20 Nm

Formation of nanocrystalline composites γ-TiAl + Ti2AlN by mechanically alloying (MA) Ti50Al50 in a N2 atmosphere and subsequent annealing treatment are investigated. The development of the microstructure was monitored by x-ray diffraction, and differential thermal analysis and transmission electron microscopy. The amorphous phase could be obtained after milling for 30 h in a nitrogen atmosphere. The TEM results show that some nanocrystalline solid solution of Al in Ti also existed in the amorphous matrix. The results of annealing treatments at different temperatures for 0.5 h on the amorphous phase obtained by MA in N2 gas for 30 h show the formation of γ-phase (TiAl) and a nitride of titanium and aluminum (Ti2AlN). Available annealing treatments could produced nanocrystalline composites of γ-TiAl and Ti2AlN with a grain size less than 20 nm. With increasing annealing temperature, the crystalline sizes of γ-TiAl and Ti2AlN increase, but the values of microhardness increase slightly.

scholarly journals Chelating Ligand-Mediated Hydrothermal Synthesis of Samarium Orthovanadate with Decavanadate as Vanadium Source

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Quanguo Li ◽  
Wenli Zuo ◽  
Feng Li
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Ph Value ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Reaction Systems ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Hydrothermal Approach

A new ethylenediaminetetraacetic acid- (EDTA-) mediated hydrothermal route to prepare chrysanthemum-shaped samarium orthovanadate (SmVO4) nanocrystals with decavanadate (K6V10O28·9H2O) as vanadium source has been developed. The present hydrothermal approach is simple and reproducible and employs a relatively mild reaction temperature. The EDTA, pH value, and temperature of the reaction systems play important roles in determining the morphologies and growth process of the SmVO4products. The products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence spectra (PL), and UV-Vis spectroscopy.

scholarly journals A Simple Approach to the Synthesis of Hexagonal-Shaped Silver Nanoplates

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
G. Cynthia Jemima Swarnavalli ◽  
V. Joseph ◽  
V. Kannappan ◽  
D. Roopsingh
Keyword(s):  
Simple Approach ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silver Nanoplates ◽  
Transmission Electron ◽  
Growth Method ◽  
Xrd Studies ◽  
20 Nm ◽  
Faceted Particles

This paper deals with the synthesis of hexagonal-shaped silver nanoplates with diameters ranging from 15 to 20 nm along with a smooth nanobulk of 120 nm. These nanoplates were prepared by a kinetically controlled solution growth method using mild reducing agent dextrose, polyvinylpyrrolidone (PVPMw40 kDa) as the capping agent and urea as a habit modifier and at a moderate temperature of50°C. The crystal structure of the highly faceted particles consists mostly of (111) surfaces as revealed by both X-ray diffraction (XRD) studies and transmission electron microscopy (TEM).

scholarly journals Structural and Enhanced Optical Properties of Stabilized γ‒Bi2O3 Nanoparticles: Effect of Oxygen Ion Vacancies

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1023 ◽  
Author(s):  
Ashish Chhaganlal Gandhi ◽  
Chia-Liang Cheng ◽  
Sheng Yun Wu
Keyword(s):  
Room Temperature ◽  
Excess Oxygen ◽  
Ambient Atmosphere ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Band Emission ◽  
Oxygen Ion ◽  
Integrated Intensity ◽  
Effect Of Oxygen

We report the synthesis of room temperature (RT) stabilized γ–Bi2O3 nanoparticles (NPs) at the expense of metallic Bi NPs through annealing in an ambient atmosphere. RT stability of the metastable γ–Bi2O3 NPs is confirmed using synchrotron radiation powder X-ray diffraction and Raman spectroscopy. γ–Bi2O3 NPs exhibited a strong red-band emission peaking at ~701 nm, covering 81% integrated intensity of photoluminescence spectra. Our findings suggest that the RT stabilization and enhanced red-band emission of γ‒Bi2O3 is mediated by excess oxygen ion vacancies generated at the octahedral O(2) sites during the annealing process.

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

2012 ◽  
Vol 217-219 ◽  
pp. 733-736
Author(s):  
Xiu Mei Han ◽  
Shu Ai Hao ◽  
Ying Ling Wang ◽  
Gui Fang Sun ◽  
Xi Wei Qi
Keyword(s):  
Thermal Analysis ◽  
Ir Spectra ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Process ◽  
Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

CeO2/TiO2 Nanotubes Composites: Synthesis, Characterization, and Photocatalytic Properties

2012 ◽  
Vol 583 ◽  
pp. 86-90 ◽  
Author(s):  
Hai Bin Li ◽  
Xin Yong Li ◽  
Yan De Song ◽  
Shu Guang Chen ◽  
Ying Wang ◽  
...  
Keyword(s):  
Diffuse Reflectance Spectroscopy ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Electron Hole ◽  
Calcination Process ◽  
X Ray ◽  
Transmission Electron ◽  
Hole Recombination

TiO2nanotubes were prepared via a hydrothermal route. CeO2nanoparticles with diameters around 5nm were loaded onto the surface of TiO2nanotubes via a deposition approach followed by a calcination process. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy (UV-vis) were applied for the characterization of the as-prepared CeO2/TiO2nanotubes composites. The results show that CeO2particles are highly dispersed on the surface of TiO2nanotubes. The TiO2 nanotubes are modified to response to the visible light due to the combination with CeO2. The CeO2/TiO2nanotubes composites with a CeO2/TiO2atomic ratio of 2.5% show a further improvement on the photocatalytic activity for degradation of Rhodamine B in water. The presence of CeO2improves the light absorption of TiO2nanotubes and inhibits the electron-hole recombination.

Effects of Indium Incorporation on the Optical Properties of ZnO Films

2006 ◽  
Vol 11-12 ◽  
pp. 159-162 ◽  
Author(s):  
Yong Ge Cao ◽  
Lei Miao ◽  
Sakae Tanemura ◽  
Yasuhiko Hayashi ◽  
Masaki Tanemura
Keyword(s):  
Optical Transmission ◽  
Full Width Half Maximum ◽  
Structural Disorder ◽  
Band Gaps ◽  
Zno Films ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optical Band Gaps ◽  
Xrd Patterns

Transparent indium-doped ZnO (IZO) films with low In content (<6at%) were fabricated through radio-frequency (rf) helicon magnetron sputtering. Formation of In-Zn-O solid solution was confirmed by X-ray diffraction (XRD) patterns. Incorporation of indium into ZnO films enhances the optical transmission in the visible wavelength. The optical band-gaps slightly increase from 3.25eV (ZnO) to 3.28eV (In0.04Zn0.96O) and to 3.30eV (In0.06Zn0.94O) due to Burstain-Moss effect. The Urbach tail parameter E0, which is believed to be a function of structural disorder, increases from 79meV (ZnO), to 146meV (In0.04Zn0.96O), and to 173meV (In0.06Zn0.94O), which is consistent with increase of Full-Width Half-Maximum (FWHM) in corresponding XRD patterns. Decreasing in crystal quality with increasing indium concentration is also confirmed by photoluminescence spectra.

Properties of Carbon Nanofibers Prepared from Polyacrylonitrile/Poly(methyl Methacrylate) Blend

2009 ◽  
Vol 79-82 ◽  
pp. 353-356
Author(s):  
Wei Pan ◽  
Yan Chen ◽  
Xiao Wei He
Keyword(s):  
Methyl Methacrylate ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Nitrogen Atmosphere ◽  
Wet Spinning ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Methyl Methacrylate ◽  
Graphite Crystallite ◽  
Raman Microspectrometry

The polyacrylonitrile(PAN)/poly (methyl methacrylate)(PMMA) blend fibers were prepared by wet-spinning technique and carbonized over the temperature range of 400-1000°C in nitrogen atmosphere. After carbonization of the blend fibers, the PMMA component removed and the PAN component left in the form of carbon nanofibers. Morphology of the carbon nanofibers were investigated via scanning electron microscopy (SEM), and the carbonization behavior of the fibers were examined via x-ray diffraction (XRD), Raman microspectrometry. The optimal condition made carbon fibers with great L/D ratio and diameter less than 200 nm. XRD and Raman spectra shows that the PAN/PMMA blend fibers treated at 600°C produced some graphite crystallite.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

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