Synthesis of Ultrafine MgAl2O4 Powders by Nitrate-Citrate Sol-Gel Combustion Process

2008 ◽  
Vol 368-372 ◽  
pp. 407-408
Author(s):  
Long Chen ◽  
Qi Zhang ◽  
Wen Ping Chen ◽  
Yao Gang Li ◽  
Yan Mo Chen ◽  
...  
Keyword(s):  
Sol Gel ◽  
Combustion Process ◽  
Xrd Analysis ◽  
Transmission Electron Microscopy Image ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Microscopy Image ◽  
Gel Combustion ◽  
Lower Temperature

Ultrafine MgAl2O4 powders were synthesized by a nitrate-citrate sol-gel combustion process using Al(NO3)3·9H2O, Mg(NO3)2·6H2O and C6H8O7·H2O as initial materials. The result of X-ray diffraction (XRD) analysis indicated that single-phase MgAl2O4 powder could be obtained at 850 oC, which is much lower than that needed in solid-state reactions. Transmission electron microscopy image showed that the as-prepared powder was in the nano scale and little agglomerate exited. It is concluded that this process need shorter time, lower temperature, and simple equipments.

Functionalized Silicate Supported TiO2-ZnO Nanocomposite Film and its Application in Simultaneous Photocatalytic Degradation of Toxic Molecules

2013 ◽  
Vol 764 ◽  
pp. 255-265 ◽  
Author(s):  
R. Dhanalakshmi ◽  
A. Pandikumar ◽  
R. Ramaraj
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Potential Candidate ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Molar Ratios ◽  
Amine Functionalized ◽  
Transmission Electron

The TiO2-ZnO nanocomposite materials ((TiO2-ZnO)NCM) with different molar ratios (Ti:Zn) was synthesized by chemical route and dispersed in functionalized silicate sol-gel matrix (Silicate/(TiO2-ZnO)NCM)). The as prepared Silicate/(TiO2-ZnO)NCM were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis. The dispersion of the small amount of (TiO2-ZnO)NCM in silicate sol-gel matrix paves the way for the preparation of solid-state thin film photocatalyst which is advantageous for the separation of the catalyst from solution, the substrates and the reaction products. The simultaneous photoinduced oxidation of methylene blue (MB) dye and reduction of Cr (VI) to Cr (III) was examined at different amine functionalized silicate sol-gel embedded (TiO2-ZnO)NCM films. The (TiO2-ZnO)NCM dispersed into the amine functionalized silicate sol-gel matrix (TPDT) exhibited enhanced photocatalytic activity when compared to the (TiO2-ZnO)NCM without the silicate sol-gel. The functionalized silicate sol-gel supported (TiO2-ZnO)NCM is a potential candidate for energy conversion and environment remediation and cleaning applications.

Synthesis, Characterization and Bioactivity Studies of Calcium Silicate Bioceramics

2012 ◽  
Vol 584 ◽  
pp. 479-483 ◽  
Author(s):  
R. Lakshmi ◽  
Swamiappan Sasikumar
Keyword(s):  
Sol Gel ◽  
Combustion Process ◽  
Calcium Nitrate ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Sem Image ◽  
Gel Combustion ◽  
Ft Ir ◽  
Highly Porous

Wollastonite is one of the most widely used bioceramic due to its biocompatibility and bioactivity. Wollastonite (CaSiO3) was synthesized by sol-gel combustion process using citric acid as a fuel/reductant and nitrate as an oxidant. Calcium nitrate was taken as a source of calcium and tetraethyl orthosilicate was taken as the source of silicate. The obtained product was characterized by powder X-ray diffraction, Fourier - Transform Infrared spectroscopy and Scanning electron microscopy. The XRD pattern shows that the product formed is a pure and single phasic wollastonite. The FT-IR spectra revealed that there is no secondary phase present in the product. The SEM image shows that the product is highly porous. The particle size calculated using Scheerer’s formula shows that the particles are in a nano regime.

The effect of TiO2addition on the preparation and phase transformation for precursor β-spodumene powders

1994 ◽  
Vol 9 (9) ◽  
pp. 2290-2297 ◽  
Author(s):  
Moo-Chin Wang
Keyword(s):  
Electron Microscopy ◽  
Phase Transformation ◽  
Sol Gel ◽  
Peak Position ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Amorphous Powders ◽  
Lower Temperature ◽  
Dta Curves ◽  
A Minor

Fine β-spodumene-type amorphous powders were obtained through sol-gel techniques using Si(OC2H5)4, Al (OC2H5)3, LiOCH3, and Ti(OC2H5)4as the starting metal alkoxides. Differential thermal analysis (DTA), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction (ED) analysis were utilized to study the phase transformation behavior of the LAST gels. The viscosity of the LAST solution increased abruptly at longer time when the TiO2content was increased. As the TiO2content was increased, the peak position of β-spodumene phase formation in DTA curves was shifted to a lower temperature. For calcination of LAST gels at 800°-1200 °C, the crystallized phases are composed of the major phase of β-spodumene and a minor phase of rutile (TiO2). Unlike earlier studies, heating the dried LAST gels from 800 °C to 1200 °C did not show β-eucryptite, nor found γ-spodumene.

Sodium-Doped Hydroxyapatite Nanopowder through Sol-Gel Method: Synthesis and Characterization

2011 ◽  
Vol 694 ◽  
pp. 128-132 ◽  
Author(s):  
Erlani Pusparini ◽  
Iis Sopyan ◽  
Mohd. Hamdi ◽  
Singh Ramesh
Keyword(s):  
Sol Gel ◽  
Calcium Nitrate ◽  
Xrd Analysis ◽  
Sodium Concentration ◽  
Calcium Nitrate Tetrahydrate ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Nitrate Tetrahydrate

The nanocrystalline HA powders were produced through sol-gel method which employed calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4] as calcium and phosphorous precursors. Sodium ion (Na+) is one of the trace elements found in biological apatite and believed to have important effect in its performance. The concentrations of sodium dopant were varied from 0 mol% until 15 mol% by using sodium nitrate (NaNO3) as the source of dopant. Characterization of nanopowders was investigated by using X-ray diffraction (XRD), Fourier transform infra red (FTIR) and Transmission Electron Microscope (TEM). XRD analysis revealed that there are no other phases exist in the synthesized powder, evinced single phase of HA and a trend shows an increase of cristallinity with increase of sodium dopant concentration. While the TEM images showed evidence that the particle sizes were bigger with the increasing sodium concentration, showing the effect of sodium dopant on the densification of the powder.

Structural and magnetic properties of nanostructured Li–Ni–Co ferrite prepared by sol–gel method

2017 ◽  
Vol 31 (12) ◽  
pp. 1750083 ◽  
Author(s):  
Nandeibam Nilima ◽  
Mamata Maisnam ◽  
Sumitra Phanjoubam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Initial Permeability ◽  
X Ray Diffraction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Increase With Increase ◽  
Transmission Electron ◽  
Frequency Variations

Li–Ni–Co ferrite samples with compositional formula Li[Formula: see text]Ni[Formula: see text]Co[Formula: see text]Fe[Formula: see text]O4 with [Formula: see text] ranging from 0.00 to 0.1 in steps of 0.02 were prepared by sol–gel method. X-ray diffraction (XRD) analysis confirmed the formation of single phase with spinel structure in all the samples. The lattice constant evaluated from XRD data was found to increase with increase of Co[Formula: see text] substitution and crystallite size was observed in the range of 30–59 nm. The microstructure of the samples was studied by using scanning electron microscopy (SEM). Nanocrystalline nature of ferrites was also confirmed by transmission electron microscopy (TEM). [Formula: see text]–[Formula: see text] measurements were made using a vibrating sample magnetometer and hysteresis parameters such as saturation magnetization and coercivity were obtained for all compositions. The frequency variations of initial permeability and permeability loss showed a dispersive behavior for all compositions and an increase in initial permeability is observed with increase of Co[Formula: see text] substitution. The results obtained and mechanisms involved are discussed in the paper.

Nanocrystalline GdFeO3 via the gel-combustion process

2005 ◽  
Vol 20 (10) ◽  
pp. 2654-2659 ◽  
Author(s):  
S.V. Chavan ◽  
A.K. Tyagi
Keyword(s):  
Combustion Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Metal Nitrates ◽  
Transmission Electron ◽  
Expansion Behavior ◽  
High Temperature Xrd ◽  
Gel Combustion ◽  
Crystallite Sizes

Nanocrystalline GdFeO3 powder was synthesized by a combustion technique, using glycine as the fuel and the corresponding metal nitrates as oxidants. Five different molar ratios of fuel-to-oxidant were chosen to study the effect of fuel content on the phase formation and the powder properties. The powders after calcination were characterized by x-ray diffraction (XRD) and crystallite sizes calculated by x-ray line broadening. The crystallite sizes for the phase pure products after calcination at 600 °C were in the range 40–65 nm. The transmission electron microscopy observations clearly highlight the pronounced crystallinity for the propellant chemistry samples. The nature of the agglomerates was investigated by light scattering studies. The lattice thermal expansion behavior was also studied by high-temperature XRD.

scholarly journals The Influence Of NO/O2 On The NOx Storage Properties Over A Pt-Ba-Ce/γ-Al2O3 Catalyst

2019 ◽  
Vol 17 (1) ◽  
pp. 1459-1465
Author(s):  
Xuedong Feng ◽  
Jing Yi ◽  
Peng Luo
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
No Oxidation ◽  
Test Results ◽  
X Ray Diffraction ◽  
Storage Performance ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Physical And Chemical ◽  
Al2o3 Catalyst

AbstractWith the purpose of studying the influence of NO/O2 on the NOx storage activity, a Pt-Ba-Ce/γ-Al2O3 catalyst was synthesized by an acid-aided sol-gel method. The physical and chemical properties of the catalyst were characterized by X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results showed that the composition of the catalyst was well-crystallized and the crystalline size of CeO2 (111) was about 5.7 nm. The mechanism of NO and NO2 storage and NOx temperature programmed desorption (NO-TPD) experiments were investigated to evaluate the NOx storage capacity of the catalyst. Pt-Ba-Ce/γ-Al2O3 catalyst presented the supreme NOx storage performance at 350℃, and the maximum value reached to 668.8 μmol / gcat. Compared with O2-free condition, NO oxidation to NO2 by O2 had a beneficial effect on the storage performance of NOx. NO-TPD test results showed that the NOx species stored on the catalyst surface still kept relatively stable even below 350℃.

scholarly journals Microscopic study of zinc nanoparticles synthesised using thermosetting polymer

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Giriraj Tailor ◽  
Jyoti Chaudhay ◽  
Deepshikha Verma ◽  
Bhupendra Kr. Sarma
Keyword(s):  
Electron Microscope ◽  
Xrd Analysis ◽  
The Novel ◽  
X Ray Diffraction ◽  
Zinc Nanoparticles ◽  
Transmission Electron ◽  
Sem Study ◽  
Zinc Salts ◽  
Thermosetting Polymer ◽  
Low Crystalline

AbstractThe present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850 °C for 30 min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.

scholarly journals V2O3/C composite fabricated by carboxylic acid-assisted sol–gel synthesis as anode material for lithium-ion batteries

2021 ◽  
Author(s):  
G. S. Zakharova ◽  
E. Thauer ◽  
A. N. Enyashin ◽  
L. F. Deeg ◽  
Q. Zhu ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Carbon Sources ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Battery Electrode ◽  
Sol Gel Synthesis

AbstractThe potential battery electrode material V2O3/C has been prepared using a sol–gel thermolysis technique, employing vanadyl hydroxide as precursor and different organic acids as both chelating agents and carbon sources. Composition and morphology of resultant materials were characterized by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies, physical sorption, and elemental analysis. Stability and electronic properties of model composites with chemically and physically integrated carbon were studied by means of quantum-chemical calculations. All fabricated composites are hierarchically structured and consist of carbon-covered microparticles assembled of polyhedral V2O3 nanograins with intrusions of amorphous carbon at the grain boundaries. Such V2O3/C phase separation is thermodynamically favored while formation of vanadium (oxy)carbides or heavily doped V2O3 is highly unlikely. When used as anode for lithium-ion batteries, the nanocomposite V2O3/C fabricated with citric acid exhibits superior electrochemical performance with an excellent cycle stability and a specific charge capacity of 335 mAh g−1 in cycle 95 at 100 mA g−1. We also find that the used carbon source has only minor effects on the materials’ electrochemical performance.

Effect of Calcinations on Characterizations of Fabricated Nano Manganese Ferrite

2013 ◽  
Vol 634-638 ◽  
pp. 2150-2154 ◽  
Author(s):  
Rita Sundari ◽  
Tang Ing Hua ◽  
M. Rusli Yosfiah
Keyword(s):  
Sol Gel ◽  
Volatile Components ◽  
Manganese Ferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Reflectance Analysis ◽  
Transmission Electron Microscope Analysis ◽  
Electron Microscope Analysis ◽  
Nano Size

A citric acid anionic surfactant has been applied for nano manganese ferrite (MnFeO3) fabrication using sol gel method. The calcinations have been varied for 300, 600 and 800oC. The UVDR (UV-Vis Diffused Reflectance) analysis shows a high absorptive band gap after 400 nm for the 600oC calcinated MnFeO3. The DTA (Differential Thermal Analysis) profiles exhibit remarkably trapped volatile matters (H2O, CO2, and NO2) in the fabricated MnFeO3 under sol gel heat treatment at 100oC and the peaks disappeared as the calcination increased to 600oC. As the temperature elevated from 100 to 300oC, the absorption peaks of volatile components are disappeared as demonstrated clearly by the FTIR (Fourier Transform Infrared) spectra of the fabricated material, which 3393 cm-1 corresponded to OH group, 1624 cm-1 to CO group, and 1384 cm-1 to NO group. The XRD (X-Ray Diffraction) spectra show clearly the alteration process from amorphous to crystalline structure as the calcinations increased from 300 to 600oC. In addition, the TEM (Transmission Electron Microscope) analysis exhibits parts of the fabricated MnFeO3 found in cubic nano size of 15-40 nm under interested calcinations and the result is in agreement with that obtained by XRD investigation.

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