scholarly journals Structure and gas sensitive properties of oxide compositions WO3—In2O3 and WO3—CO3O4

2019 ◽  
Vol 22 (1) ◽  
pp. 53-66
Author(s):  
Yu. S. Haiduk ◽  
A. A. Khort ◽  
M. A. Mokhovikov ◽  
A. A. Savitsky
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nitrogen Dioxide ◽  
Sol Gel ◽  
Structural Features ◽  
Sensory Response ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Scanning Electron

Nanocrystalline tungsten oxide (WO3), indium oxide (In2O3), cobalt oxide (Co3O4) and mixed composites with different WO3—In2O3 and WO3—Co3O4 ratios were obtained by the sol-gel method after calcination of xerogels at 400—600 °C. The morphology, phase composition, and structural features of the materials obtained were studied by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The increase in the gas sensitivity of the joint composition compared to the initial oxides can be explained by a decrease in the crystallite size and an increase in the specific surface, as well as by the dependence of the surface state of the grains on the composition. The highest sensory response to nitrogen dioxide in both compositions lies in the range of 130—150 °C, and to carbon monoxide, above 230 °C. Low-power planar nitrogen dioxide sensors with a sensitivity of << 1 ppm and power consumption ≤ 85 mW were produced.

scholarly journals Structural properties of the composites (BaFe12O19/Ni0.3Cu0.2Zn0.5Al-0.5Fe1.5O4) prepared by sol-gel auto combustion

2019 ◽  
Vol 24 (4) ◽  
pp. 69
Author(s):  
Mohammed Mustafa Rashid1 ◽  
Sabah J. Fathi2 ◽  
Rafea A. Munef ◽  
Bilal Omer Ahmed1
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Sol Gel ◽  
Structural Features ◽  
Nano Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion ◽  
Scanning Electron

The nanocomposites ferrites (BaFe12O19/Ni0.3Cu0.2Zn0.5Al­0.5Fe1.5O4) with (x=10,25,50,75,90%) were prepared by sol-gel auto combustion. The micro-structural features of the samples were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results were compared which show that the grain size of the nano composites which prepared by sol-gel auto combustion about (25-46) nm.   http://dx.doi.org/10.25130/tjps.24.2019.075  

scholarly journals Structural and optical properties of SnO2–Al2O3 nanocomposite synthesized via sol-gel route

2015 ◽  
Vol 33 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Neeraj K. Mishra ◽  
Chaitnaya Kumar ◽  
Amit Kumar ◽  
Manish Kumar ◽  
Pratibha Chaudhary ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Properties ◽  
Sol Gel ◽  
Physical Interaction ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Sensing Applications ◽  
Scanning Electron

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

Preparation of Borosilicate Xerogel and Research on its Mineralization

2012 ◽  
Vol 476-478 ◽  
pp. 2059-2062
Author(s):  
Chen Wang ◽  
Ya Dong Li ◽  
Gu Qiao Ding
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Ph Value ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compositional Changes ◽  
Scanning Electron

Tributyl borate was first adopted for the introduction of boron in the preparation of bioactive borosilicate xerogel by sol-gel method. The xerogel reacted continuously in 0.25M K2HPO4 solution with a starting pH value of 7.0 at 37 °C for 1day. The structural, morphologies and compositional changes resulting from the conversion were characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The results indicated that speed of formation of HA was cut way back on the time with the addition of boron and the induction period for the HA nucleation on the surface of the borosilicate xerogel was short than 1 days. The conversion mechanism of the borosilicate xerogels to hydroxyapaptite was also discussed.

scholarly journals Synthesis of Brushite from Phophogypsum Industrial Waste

2021 ◽  
Vol 12 (5) ◽  
pp. 6580-6588
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Industrial Waste ◽  
Sol Gel ◽  
Dicalcium Phosphate Dihydrate ◽  
X Ray Diffraction ◽  
Characterization Methods ◽  
X Ray ◽  
Phosphate Dihydrate ◽  
Scanning Electron

Dicalcium phosphate dihydrate (DCPD) nanoparticles, also known as brushite, are considered an important bioceramic compound. In this study, brushite was prepared from Moroccan phosphogypsum (PG) using a new sol-gel method. A two-step technique undergoes the synthesis of brushite, the preparation of anhydrite from PG followed by adding phosphoric acid in the presence of sodium hydroxide. The morphology, the chemical composition, and the crystallites size were obtained using Scanning Electron Microscopy (SEM-EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), respectively. According to the Debye-Scherrer equation, these characterization methods indicated that the synthesized brushite was highly pure according to the Ca/P ratio of 1.14 and an average crystallites size estimated at 66 nm. These results proved that the brushite was successfully synthesized from Moroccan phosphogypsum.

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

SiO2ZrO2 Thin Films as Low Temperature NO2 and O3 Sensors

2015 ◽  
Vol 1088 ◽  
pp. 81-85 ◽  
Author(s):  
T.N. Myasoedova ◽  
Victor V. Petrov ◽  
Nina K. Plugotarenko ◽  
Dmitriy V. Sergeenko ◽  
Galina Yalovega ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Operating Temperatures ◽  
Scanning Electron

Thin SiO2ZrO2films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO2in the SiO2matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO2and O3impurity in air at lower operating temperatures in the range of 30-60°C.

Biomorphic TiO2 Ceramics Prepared from Cotton Stalk

2012 ◽  
Vol 602-604 ◽  
pp. 526-529
Author(s):  
Qing Wang ◽  
Lin Zhang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
High Temperature ◽  
Sol Gel ◽  
Cotton Stalk ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic TiO2 was prepared by high temperature pyrolysis and a modified sol-gel route. The morphology and microstructure of TiO2 samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the biomorphic TiO2 mainly consists of rutile TiO2, and replicates the shape and part microstructure of the carbon template.

Synthesis of Powders Nanometer Al2O3 Method by Sol-Gel

2012 ◽  
Vol 727-728 ◽  
pp. 9-13
Author(s):  
Suzana Arleno S. Santos ◽  
Eduardo Sousa Lima ◽  
Luis Henrique Leme Louro ◽  
Célio Albano da Costa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Thermogravimetric Analysis ◽  
Calcination Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Size ◽  
Scanning Electron

This study aimed to produce nanometric powders of alumina by sol-gel route. Six samples were produced by varying the amount of water for dilution of aluminum nitrate and the calcination temperature. The final products were evaluated by thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and particle size. It could be noticed that, beyond the time of gelation and calcination temperature, the addition of water also influenced the average size of the clusters.

Synthesis of Zinc Doped-Biphasic Calcium Phosphate Nanopowder via Sol-Gel Method

2012 ◽  
Vol 531-532 ◽  
pp. 614-617 ◽  
Author(s):  
Gunawan ◽  
I. Sopyan ◽  
A. Naqshbandi ◽  
S. Ramesh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Phosphate ◽  
Field Emission ◽  
Biphasic Calcium Phosphate ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Scanning Electron

Biphasic calcium phosphate powders doped with zinc (Zn-doped BCP) were synthesized via sol-gel technique. Different concentrations of Zn have been successfully incorporated into biphasic calcium (BCP) phases namely: 1%, 2%, 3%, 5%, 7%, 10% and 15%. The synthesized powders were calcined at temperatures of 700-900°C. The calcined Zn-doped BCP powders were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential and thermogravimetric analysis (TG/DTA) and field-emission scanning electron microscopy (FESEM). X-ray diffraction analysis revealed that the phases present in Zn-doped are hydroxyapatite, β- TCP and parascholzite. Moreover, FTIR analysis of the synthesized powders depicted that the bands of HPO4 increased meanwhile O-H decreased with an increase in the calcination temperature. Field emission scanning electron microscopy (FESEM) results showed the agglomeration of particles into microscale aggregates with size of the agglomerates tending to increase with an increase in the dopant concentration.

Synthesis of Ultra-Fine Conducting Polyaniline Micro/Nanotubes Using Fiber Template and Their NH3 Gas Sensitivity

2007 ◽  
Vol 7 (12) ◽  
pp. 4515-4521 ◽  
Author(s):  
Bo Xue ◽  
Shaoyan Qi ◽  
Jian Gong ◽  
Yu Gao ◽  
Shuang Yao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Transmission Electron ◽  
Conducting Polyaniline ◽  
Inner Diameter ◽  
Scanning Electron

We have recently fabricated ultra-fine conducting polyaniline (PANI) tubes with high gas sensitivity. This route includes two steps. Firstly, aniline polymerizes on the surface of a suitable fiber template prepared by electrospun nitrocellulose (NC). Then, the NC fiber template is dissolved and the ultra-fine PANI tubes are obtained. The structure of the conducting PANI tubes is characterized by IR spectrum and wide-angle X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results indicate that the PANI shows the shape of ultra-fine tubes with average inner diameter of 250–350 nm. The wall thickness of the ultra-fine PANI tubes increases with increasing the content of oxidant. The conductivity of the doped PANI tubes is about 6 9 × 10−2 S. The results of gas sensitivity of the ultra-fine PANI tubes indicate that the PANI tubes can act as "electronic nose" to detect toxic NH3 gas below 20 ppm.

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