TEM INVESTIGATIONS ON CNT-ADDED HEXAGONAL WO3 FILMS FOR SENSING APPLICATIONS

NANO ◽  
2008 ◽  
Vol 03 (04) ◽  
pp. 223-227 ◽  
Author(s):  
KATARÍNA SEDLÁCKOVÁ ◽  
RADU IONESCU ◽  
CSABA BALÁZSI
Keyword(s):  
Carbon Nanotubes ◽  
Tungsten Oxide ◽  
Sodium Tungstate ◽  
Acidic Precipitation ◽  
Temperature Range ◽  
Sensing Applications ◽  
Hexagonal Tungsten Oxide ◽  
Tungstate Solution ◽  
Average Size ◽  
Hazardous Gas

In this work, nanocrystalline hexagonal tungsten oxide was prepared by acidic precipitation from sodium tungstate solution. TEM studies of nanopowders showed that the average size of the hexagonal nanoparticles is 30–50 nm. Novel nanocomposites were prepared by embedding a low amount of gold-decorated carbon nanotubes into the hex- WO 3 matrix. The addition of MWCNTs lowered the temperature range of sensitivity of hex- WO 3 nanocomposites to NO 2 hazardous gas. The sensitivity of hex- WO 3 with Au -decorated MWCNTs to NO 2 is at the temperature range between 25°C and 250°C.

Hexagonal WO3 Films with Carbon Nanotubes for Sensing Applications

2008 ◽  
Vol 589 ◽  
pp. 67-71 ◽  
Author(s):  
Csaba Balázsi ◽  
Radu Ionescu ◽  
Katarína Sedlácková
Keyword(s):  
Carbon Nanotubes ◽  
Tungsten Oxide ◽  
Sodium Tungstate ◽  
Acidic Precipitation ◽  
Temperature Range ◽  
Sensing Applications ◽  
Hexagonal Tungsten Oxide ◽  
Tungstate Solution ◽  
Average Size ◽  
Hazardous Gas

In this work, nanocrystalline hexagonal tungsten oxide was prepared by acidic precipitation from sodium tungstate solution. TEM studies of nanopowders showed that the average size of the hexagonal nanoparticles is 30-50 nm. Novel nanocomposites were prepared by embedding a low amount of gold decorated carbon nanotubes into the hex-WO3 matrix. The addition of MWCNTs lowered the temperature range of sensitivity of hex-WO3 nanocomposites to NO2 hazardous gas. The sensitivity of hex - WO3 with Au-decorated MWCNTs to NO2 is at the temperature range between 25°C and 250°C.

Nanosize hexagonal tungsten oxide for gas sensing applications

2008 ◽  
Vol 28 (5) ◽  
pp. 913-917 ◽  
Author(s):  
Csaba Balázsi ◽  
Lisheng Wang ◽  
Esra Ozkan Zayim ◽  
Imre Miklós Szilágyi ◽  
Katarína Sedlacková ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Gas Sensing ◽  
Sensing Applications ◽  
Hexagonal Tungsten Oxide

scholarly journals Explosive Molecule Sensing at Lattice Defect Sites in Metallic Carbon Nanotubes

2021 ◽  
Author(s):  
Manasi Doshi ◽  
Eric Paul Fahrenthold
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Experimental Research ◽  
Gas Sensing ◽  
Lattice Defect ◽  
Sensing Mechanism ◽  
Defect Sites ◽  
Chemiresistive Sensing ◽  
Hazardous Gas

Explosives and hazardous gas sensing using carbon nanotube (CNT) based sensors has been a focus of considerable experimental research. The simplest sensors have employed a chemiresistive sensing mechanism, and rely...

scholarly journals ZnWO4 Nanoparticle Scintillators for High Resolution X-ray Imaging

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1721
Author(s):  
Heon Yong Jeong ◽  
Hyung San Lim ◽  
Ju Hyuk Lee ◽  
Jun Heo ◽  
Hyun Nam Kim ◽  
...  
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
High Resolution ◽  
Tungsten Oxide ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
Average Size ◽  
And Tungsten

The effect of scintillator particle size on high-resolution X-ray imaging was studied using zinc tungstate (ZnWO4) particles. The ZnWO4 particles were fabricated through a solid-state reaction between zinc oxide and tungsten oxide at various temperatures, producing particles with average sizes of 176.4 nm, 626.7 nm, and 2.127 μm; the zinc oxide and tungsten oxide were created using anodization. The spatial resolutions of high-resolution X-ray images, obtained from utilizing the fabricated particles, were determined: particles with the average size of 176.4 nm produced the highest spatial resolution. The results demonstrate that high spatial resolution can be obtained from ZnWO4 nanoparticle scintillators that minimize optical diffusion by having a particle size that is smaller than the emission wavelength.

scholarly journals A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Waris Obitayo ◽  
Tao Liu
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Composite Films ◽  
Strain Sensors ◽  
Voltage Response ◽  
Strain Sensing ◽  
Multiwalled Carbon ◽  
Sensing Applications ◽  
Mechanical Deformations ◽  
Electrical Resistivities

The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

scholarly journals Synthesis of Fe3O4/Pt Nanoparticles Decorated Carbon Nanotubes and Their Use as Magnetically Recyclable Catalysts

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Hongkun He ◽  
Chao Gao
Keyword(s):  
Carbon Nanotubes ◽  
Pt Nanoparticles ◽  
Reduction Reaction ◽  
Raw Material ◽  
Synthesis Process ◽  
High Catalytic Activity ◽  
Hydrolysis Method ◽  
Recyclable Catalysts ◽  
Temperature Solution ◽  
Average Size

We report a facile approach to prepare Fe3O4/Pt nanoparticles decorated carbon nanotubes (CNTs). The superparamagnetic Fe3O4nanoparticles with average size of4∼5 nm were loaded on the surfaces of carboxyl groups functionalized CNTs via a high-temperature solution-phase hydrolysis method from the raw material of FeCl3. The synthesis process of magnetic CNTs is green and readily scalable. The loading amounts of Fe3O4nanopartilces and the magnetizations of the resulting magnetic CNTs show good tunability. The Pt nanopaticles with average size of 2.5 nm were deposited on the magnetic CNTs through a solution-based method. It is demonstrated that the Fe3O4/Pt nanoparticles decorated CNTs have high catalytic activity in the reduction reaction of 4-nitrophenol and can be readily recycled by a magnet and reused in the next reactions with high efficiencies for at least fifteen successive cycles. The novel CNTs-supported magnetically recyclable catalysts are promising in heterogeneous catalysis applications.

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