Tin-Doped Hematite Nanoparticles for Gas-Sensing Applications

2005 ◽  
Vol 900 ◽  
Author(s):  
Monica Sorescu ◽  
Lucian Diamandescu ◽  
Doina Tarabasanu-Mihaila
Keyword(s):  
Gas Sensing ◽  
Molar Fraction ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Hematite Nanoparticles ◽  
Sensing Applications ◽  
Particle Dimension ◽  
The Mean ◽  
Tin Content

ABSTRACTStructural and morphological characteristics of (1-x)α-Fe2O3-xSnO2 (x=0.0-1.0) nanoparticles obtained under hydrothermal conditions have been investigated by X-ray diffraction (XRD) and Mössbauer spectroscopy. On the basis of the Rietveld structure refinements of the XRD spectra at low tin content, it was found that Sn4+ partially substitutes for Fe3+ at the octahedral sites. The mean particle dimension decreases from 70 to 6 nm as the molar fraction x increases. The estimated solubility limits in the system of tin-doped hematite nanoparticles synthesized under hydrothermal conditions are x<0.2 for Sn4+ in α-Fe2O3 and x>0.7 for Fe3+ in SnO2.

Structure-Property Relationships in the xZnO-(1-x)alpha-Fe2O3 Nanoparticle System

2006 ◽  
Vol 957 ◽  
Author(s):  
Monica Sorescu ◽  
Lucian Diamandescu ◽  
Jason Wood
Keyword(s):  
Gas Sensing ◽  
Mechanochemical Activation ◽  
Morphological Characteristics ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Structure Property Relationships ◽  
Immiscible System ◽  
Sensing Applications ◽  
Fe2o3 Nanoparticle ◽  
Nanoparticle System

ABSTRACTThe xZnO-(1-x)α-Fe2O3 nanoparticles system has been obtained by mechanochemical activation for x=0.1, 0.3 and 0.5 and for ball milling times ranging from 2 to 24 hours. Structural and morphological characteristics of the zinc-doped hematite system were investigated by X-ray diffraction (XRD) and Mössbauer spectroscopy. As ZnO is not soluble in hematite in the bulk form, the present study clearly demonstrates that the solubility limits of an immiscible system can be extended beyond the limits in the solid state by mechanochemical activation. Moreover, this synthesis route allowed us to reach nanometric particle dimensions, which would make the materials very important for gas sensing applications.

scholarly journals Synthesis and Characterization of Ceramic Nanoparticles System Based on Anatase-Doped Hematite

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Monica Sorescu ◽  
L. Diamandescu ◽  
A. Sanns ◽  
D. Proch ◽  
J. Wood ◽  
...  
Keyword(s):  
Ball Milling ◽  
Gas Sensing ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Lattice Constants ◽  
Ceramic Nanoparticles ◽  
Sensing Applications ◽  
Transmission Electron ◽  
Xrd Patterns

ThexTiO2-(1−x)α-Fe2O3ceramic nanoparticles system has been obtained by mechanochemical activation forx= 0.1 and 0.5 and for ball milling times ranging from 2 to 12 hours. Structural and morphological characteristics of the anatase-doped hematite system were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy, and transmission electron microscopy (TEM) combined with electron diffraction (ED). In the XRD patterns, we could evidence the dissolution of anatase in hematite, more pronounced forx= 0.1. The Rietveld structure of the XRD patterns yielded the dependence of the particle size and lattice constants on the amountxof Ti substitutions and as function of the ball milling time. Forx= 0.1, we observed line broadening of the Mössbauer resonances and corresponding fit with several subspectra. Forx= 0.5, it can be observed that the central doublet corresponding to superparamagnetic particles becomes more prominent. The ball milling route allowed us to reach nanometric particle dimensions, which would make the materials very promising for catalytic and gas sensing applications.

Mechanochemical Synthesis of Novel Sensor Materials

2009 ◽  
Vol 1226 ◽  
Author(s):  
Monica Sorescu ◽  
Lucian Diamandescu ◽  
Adelina Tomescu
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Gas Sensing ◽  
Mechanochemical Activation ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
Recoilless Fraction ◽  
X Ray ◽  
Immiscible System ◽  
Sensing Applications

AbstractThe xZnO-(1-x)alpha-Fe2O3 and xZrO2-(1-x)alpha-Fe2O3 nanoparticles systems have been obtained by mechanochemical activation for x=0.1, 0.3 and 0.5 and for ball milling times ranging from 2 to 24 hours. Structural and magnetic characteristics of the zinc and zirconium-doped hematite systems were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy and conductivity measurements. Using the dual absorber method, the recoilless fraction was derived as function of ball milling time for each value of the molar concentration involved. As ZnO is not soluble in hematite in the bulk form, the present study clearly illustrates that the solubility limits of an immiscible system can be extended beyond the limits in the solid state by mechanochemical activation. Moreover, this synthetic route allowed us to reach nanometric particle dimensions, which makes these materials very important for gas sensing applications.

scholarly journals Characterization of CuO thin films for gas sensing applications

2019 ◽  
Vol 14 (31) ◽  
pp. 1-12
Author(s):  
Jamal M. Rzaij
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Cupric Oxide ◽  
Laser Pulses ◽  
X Ray Diffraction ◽  
Energy Increase ◽  
Nano Structure ◽  
X Ray ◽  
Sensing Applications

Nanostructural cupric oxide (CuO) films were prepared on Si and glass substrate by pulsed laser deposition technique (PLD) using laser Nd:YAG, using different laser pulses energies from 200 to 600 mJ. The X-ray diffraction pattern (XRD) of the films showed a polycrystalline structure with a monoclinic symmetry and preferred orientation toward (111) plane with nano structure. The crystallite size was increasing with increasing of laser pulse energy. Optical properties was characterized by using UV–vis spectrometer in the wave lengthrange (200-1100) nm at room temperature. The results showed that the transmission spectrum decreases with the laser pulses energy increase. Sensitivity of NO2 gas at different operating temperatures, (50°C, 100°C, 150°C and 200°C) was calculated.

scholarly journals Mg-doped and chemo-thermally treated ZnO nanoflowers for ethanol sensing

2021 ◽  
Author(s):  
Santanu Maity ◽  
P.P Sahu ◽  
Tiju Thomas
Keyword(s):  
Gas Sensing ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Wide Range ◽  
Doped Zno ◽  
Ethanol Sensing ◽  
Better Than ◽  
Mg Doped

Abstract ZnO nanostructures are promising for a wide range of applications, including gas sensors. Ethanol sensing using ZnO remains unexplored though. In this paper, we report ethanol-sensing using un-doped ZnO nano flowers and Mg doped ZnO nano flowers. These are grown using a rather simple chemo-thermal process, making this a plausibly scalable technology. To study the structural and morphological properties of undoped ZnO and Mg doped ZnO nanoflowers, Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), x-ray diffraction and Field Emission Scanning Electron Microscopy (FESEM) are carried out. Ethanol sensing properties of undoped ZnO and Mg doped ZnO nanoflower devices are investigated toward different ethanol concentration (concentration range of 1–600 ppm at 100°C–200°C). Our findings show that 15% Mg doped ZnO nano flower is better than ZnO nano flower for ethanol gas-sensing applications.

scholarly journals W-Sn Mixed Oxides and ZnO to Detect NOx and Ozone in Atmosphere

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 836
Author(s):  
Ambra Fioravanti ◽  
Sara Morandi ◽  
Alessia Amodio ◽  
Mauro Mazzocchi ◽  
Michele Sacerdoti ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mixed Oxides ◽  
Gas Sensing ◽  
Molar Fraction ◽  
Functional Materials ◽  
X Ray Diffraction ◽  
X Ray

Thick films of zinc oxide (ZnO) in form of nanospheres or hexagonal prisms and of tungsten-tin (W-Sn) mixed oxides at nominal Sn molar fraction (0.1, 0.3 and 0.5) were prepared. The functional materials were synthesized and characterized by SEM and TEM, X-ray diffraction, specific surface area measurements, UV-Vis-NIR and IR spectroscopies. The gas sensing measurements highlighted that ZnO is more performant in form of nanoprisms, while W-Sn sensors offer a better response towards NOx and ozone with respect to pure WO3.

W–Ti–O layers for gas-sensing applications: Structure, morphology, and electrical properties

1998 ◽  
Vol 13 (6) ◽  
pp. 1568-1575 ◽  
Author(s):  
L. Sangaletti ◽  
E. Bontempi ◽  
L. E. Depero ◽  
R. Salari ◽  
M. Zocchi ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Gas Sensing ◽  
Phase Segregation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Applications ◽  
Structure Morphology ◽  
Structural And Electrical Properties ◽  
Kinetics Of ◽  
Structurally Stable

The kinetics of phase transitions and phase segregation induced by annealing temperature on the Ti–W–O gas-sensing layer was studied by x-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The main goal was to identify, on the basis of kinetics studies, structurally stable Ti–WO3 thin film phases and compare their response to polluting gases in order to determine possible correlations between structural and electrical properties of the sensing layers.

scholarly journals Impact of the thickness of Nickel oxide film for nitrogen dioxide gas sensing Applications

2017 ◽  
Vol 2 (3) ◽  
pp. 341-347
Author(s):  
Sabah J. Mezher ◽  
Ehssan S. Hassan ◽  
Marwa Abdul Muhsien Hassan ◽  
Firas S. A. Ameer
Keyword(s):  
Nitrogen Dioxide ◽  
Nickel Oxide ◽  
Gas Sensing ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Glass Substrates ◽  
Sensing Applications ◽  
Electron Microscope Analysis ◽  
Nio Films

Nickel oxide (NiO) thin films were formed by RF reactive magnetron sputtering onto glass substrates. The Argon and Oxygen partial pressure were (3.2×10-3 torr) and (2.12×10-2 torr) respectively at room temperature. The thickness of the films deposited was in the range of 50-150 nm. The thickness necessity structural, electrical and sensing properties of (NiO) films were methodically examined. X-ray diffraction method which shows polycrystalline landscape with preferred reflection peak at (200) plane. Scanning electron microscope analysis revealed that the growth of nanorods in all the films. The gas sensitivity of nitrogen dioxide gas was (67 %). It was observed that the gas sensitivity for (NiO) films was increased as film thickness increases.

scholarly journals Gas Sensing of (SnO2)1-x(ZnO)x Composite Associating with Electrical Properties

2019 ◽  
Vol 17 (43) ◽  
pp. 49-57
Author(s):  
Dunia Yas
Keyword(s):  
Tin Oxide ◽  
Gas Sensing ◽  
Charge Carrier Mobility ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Gas Concentration ◽  
Sensing Applications ◽  
Maximum Electron Density ◽  
Direct Current Conductivity ◽  
Hall Effect Measurements

Abstract Semiconductor-based gas sensors were prepared, that use n-type tin oxide (SnO2) and  tin oxide: zinc oxide composite (SnO2)1-x(ZnO)x at different x ratios using pulse laser deposition at room temperature. The prepared thin films were examined to reach the optimum conditions for gas sensing applications, namely X-ray diffraction, Hall effect measurements, and direct current conductivity. It was found that the optimum crystallinity and maximum electron density, corresponding to the minimum charge carrier mobility, appeared at 10% ZnO ratio. This ratio appeared has the optimum NO2 gas sensitivity for 5% gas concentration at 300 °C working temperature.

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