scholarly journals Review A Brief Review of Synthesis, Properties and Applications of Graphene

2020 ◽  
Vol 63 (3) ◽  
pp. 231-238
Author(s):  
Tahir Iqbal ◽  
Ahmad Raza ◽  
Aqsa Tehseen ◽  
Almas Bashir
Keyword(s):  
Electron Microscopy ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Graphene Oxides ◽  
Tunneling Electron ◽  
X Ray ◽  
The Core ◽  
Increasing Trend ◽  
Synthesis Properties ◽  
Enhanced Properties

At time when the limitation of silicon capabilities is being touched the finding of graphene and its exclusive properties of nano-scale are of utmost importance. The possible substitutes of following generation for quicker and minor electronics of present 21st century. Several methods and techniques are being experimented to produce graphene with enhanced properties to be used as a substitute for existing materials. Raman spectrophotometry, X-ray diffraction, field emission-scanning electron microscopy (FE-SEM) and tunneling electron microscopy are the characterizing techniques for the prepared graphene. Graphene is the core compound of interest for scientists for this decade and previous as well, because of its exceptional impact on many life disciplines. That is why the increasing trend in recent years for the graphene and graphene oxides is observed.    

The Influence of Introduction of Polyethylene Glycol on Synthesis of Bimodal Mesoporous γ-Al2O3

2013 ◽  
Vol 709 ◽  
pp. 89-92
Author(s):  
Xiang Li ◽  
Xin Mei Liu ◽  
Zi Feng Yan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polyethylene Glycol ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
X Ray ◽  
Transmission Electron ◽  
Increasing Trend ◽  
Opposite Tendency

In the presence of polyethylene glycol (PEG2W),bimodal mesoporous γ-Al2O3 was successfully synthesized via hydrothermal method. The samples were respectively characterized by X-ray diffraction (XRD), N2 physisorption, transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimeter (TG-DSC). Introduction of PEG2W can increase the relative crystallinity of AACH and γ-Al2O3. The BET surface area and pore volume of alumina shows an increasing trend with increasing of PEG2W content, while the pore size shows an opposite tendency. The PEG2W also plays an important role in inducing the formation of the nanorod-like alumina.

scholarly journals Synthesis and Characterization of Nano-Tungsten Oxide Precipitated onto Natural Inorganic Clay for Humidity-Sensing Applications

Ceramics ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 120-127 ◽  
Author(s):  
Ahmed Afify ◽  
Ahmed Elsayed ◽  
Mohamed Hassan ◽  
Mohamed Ataalla ◽  
Amr Mohamed ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tungsten Oxide ◽  
Diffraction Field ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Transmission Electron ◽  
Tungsten Oxide Nanoparticles ◽  
Inorganic Clay

A wet chemical method was used to obtain tungsten oxide nanoparticles from tungsten tetrachloride and natural microfibrous inorganic clay (sepiolite) as a starting material. Precipitation of tungsten oxide species onto sepiolite under basic conditions and subsequent thermal treatment was investigated, prompted by the abundance of sepiolite in nature and the useful environmental applications that could be attained. Laser granulometry, X-ray diffraction, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HR-TEM) techniques were used to study the particle-size distribution, the morphology, and the composition of the prepared sample. Our findings show the presence of tungsten oxide nanoparticles, which are less than 50 nm, on the needles of the modified sepiolite.

Preparation, Characterization and Spectroscopy of Eu3+ in Gd2O3 Nanorods

2008 ◽  
Vol 8 (3) ◽  
pp. 1398-1403 ◽  
Author(s):  
Liqin Liu ◽  
En Ma ◽  
Renfu Li ◽  
Xueyuan Chen
Keyword(s):  
Electron Microscopy ◽  
Fluorescence Spectra ◽  
Filling Factor ◽  
Energy Levels ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Excitation Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Eu3+:Gd2O3 nanorods were prepared by a hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy were used to characterize the resulting samples. Emission and excitation spectra were studied using xenon excited spectroscopic experiments at 10 K. Energy transfer from Gd3+ to Eu3+, from the band gap of the host to Eu3+, and from Eu3+ (S6) to Eu3+ (C2) was observed. The energy levels of Eu3+ at the C2 site of cubic Gd2O3 were experimentally determined according to the fluorescence spectra at 10 K, and fit well with the theoretical values. The standard deviation for the optimal fit was 12.9 cm−1. The fluorescent lifetime of 5D0 (2.3 ms at 295 K) was unusually longer than that of the bulk counterparts (0.94 ms), indicating a small filling factor (0.55) for the nanorod volume. However the lifetime of 5D1 was much shorter than that of the bulk counterparts, 65 μs at 10 K, 37 μs at 295 K.

Compositional and architectural variation in urinary calculi from nucleus to periphery: an integrated IR spectroscopy, scanning electron microscopy and powder X-ray diffraction approach

2015 ◽  
Vol 48 (6) ◽  
pp. 1794-1804 ◽  
Author(s):  
Paramita Chatterjee ◽  
Samiran Pramanik ◽  
Alok Kumar Mukherjee
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Kidney Stones ◽  
Urinary Calculi ◽  
X Ray Diffraction ◽  
Carbonated Hydroxyapatite ◽  
X Ray ◽  
The Core ◽  
Different Parts ◽  
Scanning Electron

A combination of IR spectroscopy, scanning electron microscopy (SEM) and powder X-ray diffraction has been used to analyze the compositional and architectural variation across the different parts (core, middle and outer layers) of five human urinary calculi (KS1–KS5) from eastern India. Rietveld quantitative phase analysis using X-ray powder diffraction revealed that the composition of the core regions in KS1–KS3 and KS5 is exclusively whewellite, whereas in KS4 it is a mixture of whewellite (84.5 wt%) and carbonated hydroxyapatite (15.5 wt%). While one of the renal stones, KS1, is composed of only whewellite in all three regions, a distinct variation in phase composition from the core towards the periphery has been observed in KS2–KS5. A drastic change in phase composition has been noted in KS5, with the major constituent phases in the core, middle and outer layers as whewellite (100.0 wt%), anhydrous uric acid (60.7 wt%) and carbonated hydroxyapatite (69.6 wt%), respectively. The crystallite size of whewellite in different parts of the kidney stones varies between 91 (1) and 167 (1) nm, while the corresponding sizes of the anhydrous uric acid in KS5 and carbonated hydroxyapatite in KS3 are 107 (1) and 18 (1)–20 (1) nm, respectively. SEM images of the kidney stones showed different levels of organization, resulting from an agglomeration of crystallites with diverse shapes and sizes.

scholarly journals Mechanism of Nanostructured Fluorapatite Formation from CaO, CaF2 and P2O5 Precursors by Mechanochemical Synthesis

2018 ◽  
Vol 43 (3-4) ◽  
pp. 201-210
Author(s):  
Raheleh Nikonam Mofrad ◽  
Sayed Khatiboleslam Sadrnezhaad ◽  
Jalil Vahdati Khaki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mechanochemical Synthesis ◽  
Diffraction Field ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

We determined the mechanism of mechanochemical synthesis of fluorapatite from CaO, CaF2 and P2O5 by characterisation of the intermediate compounds. We used atomic absorption spectroscopy, X-ray diffraction, field emission scanning electron microscopy, FTIR spectroscopy and transmission electron microscopy to find the transitional compounds. Investigation of the binary and ternary powder mixtures revealed the appearance of H3PO4, Ca(OH)2, Ca2P2O7 and CaCO3 as the intermediate compounds. At early stages of the milling, conversions of P2O5 to H3PO4 and CaO to Ca(OH)2 occurred in the wet atmosphere. Later, a combination of Ca(OH)2 and H3PO4 formed C a2P2O7 while the unreacted CaO was converted to CaCO3 by CO2 of the ambient atmosphere. Spherical crystalline Ca10 (PO4)6F2 particles formed after 48 hours of milling due to the reaction between Ca2P2O7, CaCO3 and CaF2.

Partitioning of Cesium in Phases Produced by Grouted Waste Injection

1983 ◽  
Vol 26 ◽  
Author(s):  
D. P. Stinton ◽  
E. W. Mcdaniel ◽  
H. O. Weerent
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Cesium ◽  
The Core ◽  
Calcium Silicates ◽  
Hydrated Calcium ◽  
Scanning Electron

ABSTRACTPhases present in injected grouts were characterized by use of optical microscopy, scanning electron microscopy, x-ray diffraction, and β-γ autoradiography. A laboratoryproduced sample containing 1 wt % stable cesium and an actual grout sheet obtained by core drilling were examined. The phases present in these samples were identified, and cesium was found to be absorbed almost entirely by illite clay agglomerates. These clay agglomerates were tightly bound within the grout structure by hydrated calcium silicates. The β-γ autoradiography of the core-drilled sample verified that cesium and other radionuclides were trapped within the 20-year-old grout and had not migrated into trapped shale fragments.

Polyol-mediated preparation of disklike (ZnSe)2·EN precursor and its conversion to ZnSe crystals with quasi-network structure

2004 ◽  
Vol 19 (5) ◽  
pp. 1369-1373 ◽  
Author(s):  
Guozhen Shen ◽  
Di Chen ◽  
Kaibin Tang ◽  
Yitai Qian
Keyword(s):  
Electron Microscopy ◽  
Network Structure ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Rapid Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Argon Stream ◽  
Absorbance Spectra ◽  
Scanning Electron

In this paper, we reported the rapid synthesis of disklike (ZnSe)2·EN precursor via a simple and convenient polyol method. Annealing the precursor in argon stream at 500 °C resulted in the formation of ZnSe crystals with unique quasi-network structure. The obtained samples were characterized by powder x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, infrared absorbance spectra, and thermogravimetric analysis. The influence of PEG200 on the final products in the system was also discussed.

Environmentally Synthesis of Metallic Oxide Short-Nanorod with Biological Compatibility by Organic Solvent Assisted Annealing Process

2013 ◽  
Vol 663 ◽  
pp. 421-425
Author(s):  
Zao Yang ◽  
Quan Hui Liu
Keyword(s):  
Electron Microscopy ◽  
Organic Solvent ◽  
Annealing Process ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Metallic Oxide ◽  
X Ray ◽  
Transmission Electron ◽  
Biological Compatibility ◽  
Future Work

Metallic oxide ZnO short-nanorod of 33-83 nm in diameters and length up to 0.3um.with biological compatibility are environmentally fabricated by organic solvent-assisted annealing pro- cess. The sample was characterized by X-ray diffraction, field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM). It demonstrates that the obtained ZnO short-nanorods have good crystal quality. A growth mechanism is proposed. This paper establish base for application of Metallic oxide short-nanorod to the area of bioscience in our future work.

Study of Ru barrier failure in the Cu/Ru/Si system

2007 ◽  
Vol 22 (9) ◽  
pp. 2505-2511 ◽  
Author(s):  
M. Damayanti ◽  
T. Sritharan ◽  
S.G. Mhaisalkar ◽  
E. Phoon ◽  
L. Chan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Reaction Mechanisms ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Failure ◽  
Transmission Electron ◽  
Secondary Ion ◽  
Scanning Electron

The reaction mechanisms and related microstructures in the Cu/Si, Ru/Si, and Cu/Ru/Si metallization system were studied experimentally. With the help of sheet resistance measurements, x-ray diffraction, field-emission scanning electron microscopy, secondary ion mass spectroscopy, and transmission electron microscopy, the metallization structure with Ru barrier layer was observed to fail completely at temperatures around 700 °C, regardless of the Ru thickness because of the formation of polycrystalline Ru2Si3 followed by Cu3Si protrusions.

Synthesis and Optical Properties of CdSe and CdSe/ZnS Core/Shell Quantum Dots

2015 ◽  
Vol 1085 ◽  
pp. 176-181
Author(s):  
Puspendu Barik ◽  
Arup Ratan Mandal ◽  
Denis V. Kuznetsov ◽  
Anna Yu. Godymchuk
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Excitation Wavelength ◽  
Core Shell ◽  
Shell Material ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
The Core ◽  
Transmission Electron

In this work, we have synthesized homogeneous, ordered CdSe and CdSe/ZnS core/shell quantum dots (QDs) by chemical route and characterized them using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Photoluminescence (PL) spectroscopy. Coating with shell material was confirmed by red shift as well as enhancement in the PL peak compared to bare QDs. DLS data showed QDs and core/shell to be stable. PL spectra are red shifted relative to the excitation wavelength. Bare QDs and the core/shell material shows a Stoke-shift of 16 and 18 meV respectively.

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