scholarly journals Synthesis and characterization of nanocrystalline copper sulfide powders

2018 ◽  
Vol 16 (38) ◽  
pp. 124-131
Author(s):  
Ulla M. Sleman
Keyword(s):  
Copper Sulfide ◽  
Average Crystallite Size ◽  
Chemical Precipitation ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Nanocrystalline Copper ◽  
Intermediate Phases ◽  
Complex Agent ◽  
Scherrer Formula

Nanocrystalline copper sulphide (Cu2-xS) powders were synthesized by chemical precipitation from their aqueous solutions composed of different molar ratio of copper sulfate dehydrate (CuSO4.5H2O) and thiorea (NH2)2CS as source of Cu+2, S-2 ions respectively, and sodium ethylene diamine tetra acetic acid dehydrate (EDTA) as a complex agent. The compositions, morphological and structural properties of the nanopowders were characterized by energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), and X-ray diffraction (XRD), respectively. The compositional results showed that the copper content was high and the Sulfur content was low for both CuS and Cu2S nanopowders. SEM images shows that all products consist of aggregate of fine nanospheres with uniform distribution and the size of the particles formed are in nanometer range. XRD results revealed that the obtained powders contains a mixture of copper sulfide phases specially the intermediate phases and the rough estimate of the average crystallite size using the Scherrer formula gives a range of values (4.1-36.9) nm.

scholarly journals Influence of pretreatment on the properties of α-Fe2O3 and the effect on photocatalytic degradation of methylene blue under visible light

2020 ◽  
Vol 82 (11) ◽  
pp. 2415-2424
Author(s):  
S. Mokhtari ◽  
N. Dokhan ◽  
S. Omeiri ◽  
B. Berkane ◽  
M. Trari
Keyword(s):  
Methylene Blue ◽  
Average Crystallite Size ◽  
Sample Surface ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Lattice Constants ◽  
Electrochemical Pretreatment ◽  
Crystal Properties ◽  
Rhombohedral Symmetry

Abstract The hematite (α-Fe2O3) nanostructures were synthesized by thermal oxidation of metal at 500 °C under atmospheric pressure. We studied the effect of the electrochemical pretreatment of the substrate before calcinations and its impact on the morphology, crystalline structure, lattice microstructural, and optical properties of α-Fe2O3. Uniform nanosheets were observed on the sample surface after calcination; their dimension and morphology were accentuated by the pretreatment, as confirmed by the SEM images. The characteristics of the nanostructures, analyzed by X-ray diffraction (XRD), revealed a rhombohedral symmetry with the space group R-3c and lattice constants: a = 0.5034 nm and c = 1.375 nm. The average crystallite size and strain, determined from the Williamson-Hall (W-H) plot, showed substantial variations after the substrate pretreatment. The Raman spectroscopy confirmed the changes in the crystal properties of the hematite submitted to pretreatment. The diffuse reflectance allowed to evaluate the optical gap which lies between 1.2 and 1.97 eV, induced by the electrochemical processing. The photocatalytic activity of α-Fe2O3 films was assessed by the degradation of methylene blue (MB) under LED light; 15% enhancement of the degradation for the pretreated specimens was noticed.

Characterization of Nano-Biphasic Calcium Phosphates Synthesized under Microwave Curing

2008 ◽  
Vol 3 ◽  
pp. 67-87 ◽  
Author(s):  
Wafa I. Abdel-Fattah ◽  
Fikry M. Reicha ◽  
Tarek A. Elkhooly
Keyword(s):  
Ph Value ◽  
Calcium Phosphates ◽  
Chemical Precipitation ◽  
Calcium Deficiency ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Curing ◽  
Tcp Phase ◽  
Diffraction Patterns

Two biphasic BCP ceramic samples were synthesized by chemical precipitation and microwave curing of calcium deficient hydroxyapatite CDHA under the same pH value and temperature but varied in their initial Ca/P molar ratio. Precipitates were characterization after thermogravimetric analysis, fourier transform infrared spectroscopy, X-ray diffraction, atomic absorption spectroscopy and TEM. Hydroxyapatite (HA) contents were measured for the two biphasic calcium phosphate (BCP) ceramics by sintering the calcium-deficient apatites (CDHA). The results reveal two condensation mechanisms of HPO42- affecting the Ca/P molar ratio after calcination. The X-ray diffraction patterns of BCP powders show the in situ formation of -TCP in the BCP powder. The amount of -TCP phase increases as the initial Ca/P molar ratio decreases due to more calcium deficiency in CDHA structure. The influence of HPO42- incorporation on increasing -TCP phase content after calcination is evaluated. TEM micrographs proved the effect of microwave curing during the preparation process on reducing of particle size to nanoscale range and the destruction of CDHA to finer HA and -TCP particles upon calcination.

Synthesis and Characterization of Silver Nanoparticles Anchored on Montmorillonite via Chemical Reduction

2016 ◽  
Vol 11 ◽  
pp. 30-37 ◽  
Author(s):  
Danica Louise S. Bonga ◽  
Ma. Manna Farrel B. Pinto ◽  
Mary Fatima T. Tayad
Keyword(s):  
Ag Nanoparticles ◽  
Sodium Citrate ◽  
Chemical Reduction ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Clay Particles ◽  
X Ray ◽  
Mean Size

Montmorillonite clay particles were decorated with silver (Ag) nanoparticles by chemical reduction of Ag nitrate with sodium citrate. X-ray diffraction (XRD) and energy dispersive X-ray spectrometry (EDS) confirmed the presence of metallic Ag on the surface of montmorillonite. The average crystallite size of the Ag nanoparticles obtained from the broadening of the 111 Ag peak ranged at 13-16 nm. On the other hand, the apparent particle sizes obtained from the SEM images were about 79-128 nm, suggesting that the nanoparticles are polycrystalline and possibly agglomerated. The increase in the concentration of reducing agent produced smaller Ag nanoparticles with narrower size distribution. The antibacterial test showed that the Ag nanoparticles, with mean size of 79 nm, adsorbed on montmorillonite were able to inhibit the growth of Staphylococcus aureus (S. aureus) with an antimicrobial index of 0.4.

Synthesis of RePO4 (Re=La, Nd, Pr, or Y) Nanowires by Chemical Precipitation in Nanochannels

2011 ◽  
Vol 181-182 ◽  
pp. 495-500 ◽  
Author(s):  
Cheng Mu ◽  
Jun Hui He
Keyword(s):  
Rare Earth ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Aao Template ◽  
Sem Images ◽  
Transmission Electron ◽  
Rare Earth Phosphate ◽  
Xrd Patterns ◽  
Uniform Diameter

Monodisperse nanowires of rare earth phosphates were synthesized by chemical precipitation method using anodic aluminum oxide (AAO) template. Scanning electron microscope (SEM) images indicated that rare earth phosphate nanowires are parallelly arranged in AAO template, all of which are in uniform diameter of about 50 nm. X-ray diffraction (XRD) patterns and high magnification transmission electron microscopy (HRTEM) images showed that the nanowires were polycrystal structure.

Fabrication of CoFe/BaFe12O19 Magnetic Nanocomposite Thin Films by Electrodeposition

2013 ◽  
Vol 829 ◽  
pp. 332-336
Author(s):  
Soheila Kharratian Khameneh ◽  
M. Heydarzadeh Sohi ◽  
Abolghasem Ataie ◽  
Saeed Mehrizi
Keyword(s):  
Thin Films ◽  
Barium Hexaferrite ◽  
Average Crystallite Size ◽  
Xrd Analysis ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Nanocomposite Thin Films ◽  
Co Precipitation ◽  
Deposited Films ◽  
Dominant Phase

A study of the incorporation of barium hexaferrite nanoparticles into a CoFe matrix by means of electrodeposition over brass substrates has been performed. Barium hexaferrite nanoparticles were prepared by co-precipitation route using solution of iron and barium nitrates with a Fe3+/Ba2+molar ratio of 8, by addition of NaOH with a OH-/NO3- molar ratio of 2. X-ray diffraction (XRD) results indicated that in a sample synthesized from aqueous solution and annealed at 900 °C for 1 hour, BaFe12O19 was the dominant phase. Field emission scanning electron microscopy (FE-SEM) showed plate-like particles of barium hexaferrite by mean diameter of 300 nm and thickness of 45 nm. CoFe-BaFe12O19 nanocomposite thin films were then electrodeposited froma Co-Fe bath containing the barium hexaferrite particles obtained in the first stage of this work. Finally, FE-SEM equipped with energy dispersive spectroscopy (EDS) analyzer and XRD analysis was applied on the deposited films, to confirm presence of the nanoparticles in the film. The average crystallite size of the deposits was around 30 nm. It was also noticed that increasing the concentration of the particles in the electroplating bath, caused a rise in the BaFe12O19 content of the deposits but had no significant effect on the composition of the CoFe matrix.

Flash Synthesis of Tetragonal-ZrO2 Nanostructures by Microwave-Induced Combustion Process

2013 ◽  
Vol 750-752 ◽  
pp. 228-231 ◽  
Author(s):  
Yan Qin Xu ◽  
Sheng Wu Du ◽  
Jun Gao ◽  
Yuan Cao ◽  
Chang Guo Chen ◽  
...  
Keyword(s):  
Combustion Process ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Hollow Structures ◽  
Different Levels

The synthesis used urea and Zr (NO3)4·5H2O as material to prepare tetragonal-ZrO2 nanocrystals through microwave-induced combustion process. The tetragonal-ZrO2 nanocrystals were characterized by X-ray diffraction (XRD). The effect of Zr4+/urea molar ratio on the synthesis of tetragonal-ZrO2 were studied. It was found that tetragonal-ZrO2 crystal would be better when the Zr4+/urea molar ratio was larger than 1:3.The SEM images of the samples showed the hollow structures formed at different levels of molar ratio of Zr4+/urea. This method is a simple but effective route to prepare tetragonal-ZrO2 nanocrystals.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

scholarly journals Temperature dependent Raman Spectroscopic Study of the Fe doped La-=SUB=-0.67-=/SUB=-Sr-=SUB=-0.33-=/SUB=-MnO-=SUB=-3-=/SUB=- Prepared Using Ball Milling Method

2019 ◽  
Vol 61 (4) ◽  
pp. 741
Author(s):  
Nidhi Astik ◽  
Prafulla K. Jha ◽  
Vasant Sathe
Keyword(s):  
Average Crystallite Size ◽  
Sem Images ◽  
Raman Spectroscopic ◽  
Calcination Temperatures ◽  
Peak Broadening ◽  
Raman Modes ◽  
Milling Method ◽  
Scherrer Formula ◽  
Xrd Patterns ◽  
Increasing Temperature

AbstractPolycrystalline samples of La_0.67Sr_0.33Mn_0.65Fe_0.35O_3 (LSMFO) were synthesized using the standard ball mill method with different calcination temperatures ranging from 800 to 1100°C for 7 h. The phase purity of these samples was confirmed using X-ray diffraction (XRD) patterns. All samples were found to have rhombohedral crystal structure with $$R\bar {3}c$$ space group. The lattice parameters, cell volume, bond angle and bond length have been obtained using the Rietveld refinement by FullProf software. The average crystallite size calculated using the Debye-Scherrer formula was found between 27 and 60 nm. Surface morphology of the prepared samples has been examined using a scanning electron microscope (SEM). SEM images show the formation of well-arranged grain sizes distributed from 240 to 400 nm, much larger than one estimated using the Scherrer formula. All tiny particles are highly agglomerated with the increasing temperature and porosity decreases with increasing temperature. An analysis of the frequency and peak broadening of Raman modes as a function of temperature clearly shows the significant temperature effect on the A _1 g and E _ g modes of LSMFO. The shifts and broadening of the A _1 g and E _ g modes are discussed in light of the oxygen sublattice distortion. Our study shows the reduction in distortion with increasing calcination temperature, which suggests a decrease in the JT effect.

Performance of Concrete with Waste Tyre and Nano ZrO2

2018 ◽  
Vol 24 (8) ◽  
pp. 5737-5741
Author(s):  
Sayandip Basak ◽  
M. Helen Santhi ◽  
Caroline Ponraj
Keyword(s):  
Compressive Strength ◽  
Average Crystallite Size ◽  
Nano Particles ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Conventional Concrete ◽  
Gel Combustion ◽  
Microscope Imaging ◽  
Electron Microscope Imaging ◽  
Combustion Technique

This paper presents the compressive strength of concrete which consists of 5% replacement of coarse aggregate with rubber aggregate, 25% replacement of cement with fly ash (Class C) and an additional amount of 0.2% of ZrO2 nanoparticles. The ZrO2 nanoparticles were synthesized using gel combustion technique where zirconium oxynitrate was used as the precursor and citric acid as the fuel in the molar ratio of 1:1.5 respectively. The synthesized ZrO2 nano particles were characterized using X-ray diffraction and the average crystallite size was found as 9.7 nm. Three types of mixes were taken into consideration; control mix (M40), rubber modified concrete mix and nano-rubber modified mix. The Scanning Electron Microscope imaging was done to study the morphology of the mixes. With the percentage of rubber aggregate replacement mentioned above there was found to be a considerable decrease in the compressive strength but on incorporation of nano ZrO2 along with rubber aggregate it was found out that there was an increase in compressive strength which even surpassed the strength of conventional concrete.

Determination of Crystallite Size in Synthetic and Natural Hydroxyapatite: A Comparison between XRD and TEM Results

2012 ◽  
Vol 620 ◽  
pp. 28-34 ◽  
Author(s):  
Soheila Rahavi ◽  
Ahmad Monshi ◽  
Rahmatollah Emadi ◽  
Ali Doostmohammadi ◽  
Hamed Akbarian
Keyword(s):  
Crystallite Size ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
Real Size ◽  
Synthetic Hydroxyapatite ◽  
Scherrer Formula ◽  
Different Sources ◽  
Natural Hydroxyapatite

The study reported here focuses on the crystallite size of synthetic hydroxyapatite (HAp) obtained using sol-gel method and natural HAp obtained by processing the natural bone. Human and camel bones were used for obtaining natural HAp. HAp particles were produced, characterized and compared for their crystallite size. The average crystallite size of the samples was derived from the X-ray Diffraction (XRD) data using the Scherrer formula and a new method called modified scherrer equation that was came by developing the Scherrer formula. The results showed the crystallite size of HAp gained from different sources were different. The crystallite size of synthetic, human and camel bone-derived HAp, were approximately 18, 23 and 29 nanometer, respectively. These values were less than those obtained from TEM images. It seems that calculated crystallite size using XRD data and Scherrer equations is less than the real size. This important finding must be taken into consideration in applying Scherrer equations.

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