scholarly journals Synthesis and Characterization of CuIn1−xGaxSe2 Semiconductor Nanocrystals

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2066
Author(s):  
Yu-Tai Shih ◽  
Yu-Ching Tsai ◽  
Der-Yu Lin
Keyword(s):  
Particle Size ◽  
Semiconductor Nanocrystals ◽  
Average Particle Size ◽  
Band Gap Energy ◽  
Chalcopyrite Structure ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Tem Analysis ◽  
Transmission Electron

In this paper, the synthesis and characterization of CuIn1−xGaxSe2 (0 ≤ x ≤ 1) nanocrystals are reported with the influences of x value on the structural, morphological, and optical properties of the nanocrystals. The X-ray diffraction (XRD) results showed that the nanocrystals were of chalcopyrite structure with particle size in the range of 11.5–17.4 nm. Their lattice constants decreased with increasing Ga content. Thus, the x value of the CuIn1−xGaxSe2 nanocrystals was estimated by Vegard’s law. Transmission electron microscopy (TEM) analysis revealed that the average particle size of the nanocrystals agreed with the results of XRD. Well-defined lattice fringes were shown in the TEM images. An analysis of the absorption spectra indicated that the band gap energy of these CuIn1−xGaxSe2 nanocrystals was tuned from 1.11 to 1.72 eV by varying the x value from 0 to 1. The Raman spectra indicated that the A1 optical vibrational mode of the nanocrystals gradually shifted to higher wavenumber with increasing x value. A simple theoretical equation for the A1 mode frequency was proposed. The plot of this equation showed the same trend as the experimental data.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

The Aggregation Study and Characterization of Silver Nanoparticles

2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Average Particle Size ◽  
Average Particle ◽  
Transmission Electron ◽  
Vis Spectroscopy

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.

scholarly journals Synthesis and characterization of the aluminium phosphates modified with ammonium, calcium and molybdenum by hydrothermal method

2016 ◽  
Vol 18 (2) ◽  
pp. 131-139
Author(s):  
Kinga Łuczka ◽  
Barbara Grzmil ◽  
Bogumił Kic ◽  
Krzysztof Kowalczyk
Keyword(s):  
Particle Size ◽  
Physicochemical Parameters ◽  
Average Particle Size ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Influence Of Process Parameters ◽  
Molar Ratios ◽  
Aluminum Phosphates ◽  
The Individual

Abstract Synthesis and characterization of the aluminum phosphates modified with ammonium, calcium and molybdenum were conducted. The influence of process parameters (reactive pressure and molar ratios) in the reaction mixture were studied. The contents of the individual components in the products were in the range of: 10.97–17.31 wt% Al, 2.65–13.32 wt% Ca, 0.70–3.11 wt% Mo, 4.36–8.38 wt% NH3, and 35.12–50.54 wt% P2O5. The materials obtained in the experiments were characterized by various physicochemical parameters. The absorption oil number was in the range from 67 to 89 of oil/100 g of product, the surface area was within the range of 4–76 m2/g, whereas the average particle size of products reached 282–370 nm. The Tafel tests revealed comparable anticorrosive properties of aluminum phosphates modified with ammonium, calcium, molybdenum in comparison with commercial phosphate.

scholarly journals Structural and Optical Characterization of ZnO Nanoparticles Synthesized by Microemulsion Route

2013 ◽  
Vol 19 ◽  
pp. 26-36 ◽  
Author(s):  
Harish Kumar ◽  
Renu Rani
Keyword(s):  
Zno Nanoparticles ◽  
Thermal Studies ◽  
Average Particle Size ◽  
Band Gap Energy ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Visible Spectra ◽  
Ft Ir

ZnO nanoparticles were synthesized by microemulsion route in W/S ratio of 5 at room temperature. X-ray diffraction (XRD) pattern reveals wurtzite structure of ZnO nanoparticles. Rod shape of ZnO nanoparticles of average particle size 10.0 to 12.0 nm were observed by transmission electron microscopy. FT-IR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and presence of Zn-O bonding. Thermal studies were carried out by the differential scanning calorimeter (DSC) techniques. In addition, UV-Visible spectra were employed to estimate the band gap energy of ZnO nanoparticles.

Synthesis and Characterization of Alginate-Based Hydrogel Microbeads for Magnesium Release

2016 ◽  
Author(s):  
Shalil Khanal ◽  
Udhab Adhikari ◽  
Nava P. Rijal ◽  
Devdas Pai ◽  
Jagannathan Sankar ◽  
...  
Keyword(s):  
Particle Size ◽  
Tissue Injury ◽  
Average Particle Size ◽  
In Vitro Release ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Release Study ◽  
Vitro Release

Magnesium injection is a suitable approach for replenishment of its ions (Mg++) during neural or tissue injury and stroke to avoids risks associated with abnormally low level of Mg++ in blood. In this study, alginate encapsulated magnesium sulfate microbeads were fabricated by the electrospraying technique for Mg++ delivery. Microbeads were evaluated for particle size and surface morphology using inverted optical microscopy and scanning electron microscopy (SEM) respectively. Average particle size of 200–500 μm for hydrated and 50–200 μm for dry beads were observed. An in vitro release study of Mg++ was performed; revealing a cumulative release of ∼50% within first 24 h. This strategy can potentially be useful for the targeted local delivery of magnesium at required concentrations and subsequently enhance the therapeutic efficacy of magnesium in treating tissue injury or stroke.

scholarly journals PREPARATION AND STUDY OF FERRITE GARNET R3Fe5O12 (R=Y, Gd, Dy) NANOPARTICLES

2012 ◽  
Vol 15 (2) ◽  
pp. 27-34
Author(s):  
Nguyet Thi Thuy Dao ◽  
Duong Phuc Nguyen ◽  
Hien Duc Than
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Average Particle Size ◽  
Particle Morphology ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Ferrite Garnet ◽  
Transmission Electron ◽  
Scherrer Formula

This paper presents the synthesis and characterization of Y3Fe5O12, Gd3Fe5O12 and Dy3Fe5O12 nanoparticles by sol-gel method using initial salts solution of Y(NO3)3, Gd(NO3)3, Dy(NO3)3, Fe(NO3). The lattice constant, crystallite size and particle morphology of these ferrite garnet nanoparticles were studied by using X-ray diffraction and transmission electron microscopy (TEM). The results showed that the garnet samples prepared by this method were formed at 800oC, which is lower than the sintering temperature for ceramic bulk samples (1400oC). The particle size is in the range 25- 40 nm as observed via TEM image and the average particle size was found to be 37nm using Debye- Scherrer formula.

Synthesis and Characterization of Nickel Aluminate Spinel (NiAl2O4) Prepared from the Equilibrium Mixture of Al2O3 and NiO

2015 ◽  
Vol 797 ◽  
pp. 391-399
Author(s):  
Justyna Zygmuntowicz ◽  
Aleksandra Miazga ◽  
Łukasz Kamiński ◽  
Katarzyna Konopka
Keyword(s):  
Particle Size ◽  
Solid Phase ◽  
Average Particle Size ◽  
Equilibrium Mixture ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Nickel Aluminate ◽  
X Ray

The aim of this study was to synthesis and characterization of nickel aluminate spinel (NiAl2O4) prepared of the equilibrium mixture of Al2O3 and NiO. The materials were produced by the solid phase synthesis. In the experiments the following powders were used: α-Al2O3 TM-DAR from Taimei Chemicals (Japan) of an average particle size 133 nm and density 3.96g/cm3 and NiO powder from Sigma-Aldrich of an average particle size 200 nm and density 6.67 g/cm3. The preliminary calcination was carried out at two temperatures: 1000°C and 1200°C. The final sintering of the samples were performed at 1600°C. The characteristics of the powder after calcination and sintered samples were performed using X-ray diffraction studies (XRD), energy dispersive X-ray analysis (EDS) and scanning electron microscopy (SEM). The study of composites confirmed the presence of nickel aluminate (NiAl2O4) in whole volume of the material.

Synthesis and Characterization of Bimetallic Fe/Co Nanocatalyst on CNTs for Fischer-Tropsch Reaction

2012 ◽  
Vol 16 ◽  
pp. 9-14 ◽  
Author(s):  
Sardar Ali ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Temperature Programmed

Cobalt and iron are common catalysts used in the Fischer-Tropsch (FT) reaction. This paper presents the synthesis and characterization of monometallic and bimetallic cobalt and iron nanoparticles supported on carbon nanotubes (CNTs). The CNTs-supported nanocatalysts were synthesized by a wet impregnation method at various ratios of Fe:Co. The physicochemical properties of the samples were analyzed by H2-temperature programmed reduction (TPR), CO and H2-chemisorption analyses, transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The effects of incorporation of Fe into Co on the physicochemical properties of Co/CNTs in terms of degree of reduction, CO and H2 chemisorptions and morphologies were investigated. TEM showed that metal nanoparticles were well dispersed on the external surface and inside the CNTs. For monometallic Co/CNTs and Fe/CNTs, the average metal particle size was 5±1 nm and 6±1 nm, respectively. For the bimetallic 70Co30Fe/CNTs nanocatalysts, the average particle size was found to be 4±1 nm. Metal particles attached to the outer walls were bigger than the ones inside the CNTs. H2-TPR analysis of Co/CNTs indicated two temperature regions at 330°C (low temperature) and 491°C (high temperature). The incorporation of iron into cobalt nanocatalysts of up to 30 % of the total metal loading enhanced the catalyst’s H2 and CO chemisorptions capacities and reducibility.

scholarly journals Synthesis and Characterization ofLiNiO2Nanopowder with Various Chelating Agents

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Mehrdad Balandeh ◽  
Sirous Asgari
Keyword(s):  
Particle Size ◽  
Intensity Ratio ◽  
Metal Ion ◽  
Chelating Agents ◽  
Average Particle Size ◽  
Chelating Agent ◽  
Molar Ratio ◽  
Average Particle ◽  
Tem Analysis ◽  
Transmission Electron

LiNiO2powders were synthesized with acrylic acid, citric acid, oxalic acid, and triethanolamine (TEA) as a chelating agent. CrystallizedLiNiO2was synthesized in air at a calcinations temperature of 500∘Cfor 12 hours, when the molar ratio of chelating agents to total metal ion (RPM) was 1.0. The TEA-assisted method had the highest intensity ratio of (003)/(104) peaks of X-ray diffraction (XRD) spectrum. The transmission electron microscopy (TEM) analysis indicates that the sample prepared with triethanolamine obtained the smallest particle size with average particle size of only 12 nm. The results indicate that chelating agents have an important role in the intensity ratio of (003)/(104) peaks of XRD spectrum, size and shape of powders.

scholarly journals Behavior of Particle Size Distributions, Means and BET Values in Ideal and Non-Ideal Morphology Systems in a TEM

2004 ◽  
Vol 12 (1) ◽  
pp. 30-33
Author(s):  
Paul Beauregard
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Average Particle Size ◽  
Atomic Layer ◽  
Average Particle ◽  
Tem Analysis ◽  
Transmission Electron ◽  
New Instrument ◽  
The Cost

Historically, one of the first jobs performed by the new instrument called a “transmission electron microscope” (TEM) was the determination of particle size and distribution. Particle size is still important in controlling the properties of sub-micron and nanoparticle products. The width and average particle size can determine the light scattering properties of a pigment like TiO2, for example. The cost of installing a TEM facility and TEM sample preparation issues makes TEM analysis expensive and labor intensive. So decades ago, nitrogen BET (Brunauer, Emmett, and Teller) surface area determinations were used on sub-micron powders and pigments to minimize these costs. The BET measurement of the exposed external surface area of a material is made by detecting and measuring the amount of nitrogen given off after absorption, assuming one atomic layer of nitrogen is adsorbed.

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