STRUCTURAL, OPTICAL AND GAS SENSING PROPERTIES OF ZnO, SnO2 AND ZTO NANOSTRUCTURES

NANO ◽  
2010 ◽  
Vol 05 (04) ◽  
pp. 185-194 ◽  
Author(s):  
O. A. FOUAD ◽  
G. GLASPELL ◽  
M. S. EL-SHALL
Keyword(s):  
Tin Dioxide ◽  
Driving Forces ◽  
Gas Sensing ◽  
Average Particle Size ◽  
Average Particle ◽  
Metal Powders ◽  
Semiconducting Nanostructures ◽  
20 Nm ◽  
Emission Studies ◽  
Sensing Characteristics

Tetrapods, nanobelts and polyhedron-shape like zinc oxide (ZnO) , tin dioxide (SnO2) nanostructures and ZnO/ZnSnO3/Zn2SnO4 (ZTO) composite functional semiconducting nanostructures have been synthesized successfully by the vapor–solid growth process. XRD analyses showed that ZnO with wurtzite, SnO2 with rutile and zinc stannate (ZnSnO3) and/or dizinc stannate (Zn2SnO4) with polyhedral crystal structure were condensed from the vapor phase when Zn and/or Sn metal powders individually or mixed were used as the starting materials. The driving forces for growth of these nanostructures were found to be vapor density, temperature, pressure and place of deposition from the source materials. Typically, the ZnO nanobelts have lengths of several hundred of nanometers and widths of about 10–15 nm. The average particle size of SnO2 are in the range of about 10–20 nm. Uniform hexagonal-shaped crystals of ZnO/ZnSnO3/Zn2SnO4 composite in the range of 50–300 nm as estimated from TEM images are observed. Based on the TEM, optical absorption and emission studies and the CO gas sensing characteristics of the prepared materials showed good crystal quality implying that the ZnO , SnO2 and ZnO/ZnSnO3/Zn2SnO4 nanostructures may suggest possible applications in optoelectronic devices and chemical gas sensors.

scholarly journals Obtaining the conductive SnO2 films by chemical bath deposition method

2019 ◽  
Vol 60 (11) ◽  
pp. 1-10
Author(s):  
Vladislav I. Rogozin ◽  
◽  
Vyacheslav F. Markov ◽  
Larisa N. Maskaeva ◽  
Anastasia E. Krasovskaya ◽  
...  
Keyword(s):  
Tin Dioxide ◽  
Solid Phase ◽  
Average Particle Size ◽  
Ammonium Fluoride ◽  
Contact Layer ◽  
Average Particle ◽  
Solution Ph ◽  
Before And After ◽  
Initial Salt ◽  
Conductive Properties

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

scholarly journals Oxide Nanomaterials Based on SnO2 for Semiconductor Hydrogen Sensors

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
George Fedorenko ◽  
Ludmila Oleksenko ◽  
Nelly Maksymovych
Keyword(s):  
Tin Dioxide ◽  
Sol Gel ◽  
Average Particle Size ◽  
Fast Response ◽  
Average Particle ◽  
Hydrogen Sensors ◽  
Measuring Range ◽  
X Ray ◽  
Response And Recovery ◽  
Good Repeatability

Nanosized tin dioxide with an average particle size of 5.3 nm was synthesized by a sol-gel method and characterized by IR spectroscopy, TEM, X-ray, and electron diffraction. The obtained SnO2 can be used as initial material for creation of gas-sensitive layers of adsorption semiconductor sensors. Addition of palladium into the initial nanomaterial allows to improve response to hydrogen of such sensors in comparison with sensors based on undoped SnO2 and provides fast response and recovery time, a wide measuring range of hydrogen content in air ambient, and good repeatability of the sensor signal. Such promising properties could make useful the sensors based on these nanomaterials for devices intended to determine hydrogen in air.

Ammonia-etching-assisted nanotailoring of manganese silicate boosts faradaic capacity for high-performance hybrid supercapacitors

2020 ◽  
Vol 4 (5) ◽  
pp. 2220-2228 ◽  
Author(s):  
Xueying Dong ◽  
Yifu Zhang ◽  
Qiang Chen ◽  
Hanmei Jiang ◽  
Qiushi Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
High Performance ◽  
Average Particle Size ◽  
Average Particle ◽  
Manganese Silicate ◽  
Hybrid Supercapacitors ◽  
20 Nm

Nanotailoring of active manganese silicate with an average particle size of about 20 nm is realized by an ammonia-etching-assisted route, delivering a 3.55-times higher faradaic capacity than the traditional yolk–shell counterpart in hybrid supercapacitors.

Inducing the magnetic character in reduced graphene oxide through incorporation of Fe2O3 nanoparticles

2017 ◽  
Vol 31 (15) ◽  
pp. 1750118 ◽  
Author(s):  
Abdur Rauf ◽  
Syed Sohail Ahmad Shah ◽  
Sobia Allah Rakha ◽  
Munazza Gul ◽  
Ishaq Ahmad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Average Particle Size ◽  
Hybrid Structures ◽  
Average Particle ◽  
Multilayer Graphene ◽  
Magnetic Devices ◽  
Reduced Graphene ◽  
20 Nm

A chemical two-step approach based on solvothermal technique has been adopted to synthesize the reduced graphene oxide (rGO)/Fe2O3 hybrid materials. The rGO was prepurified by acidic treatment, followed by sensitization to attach the desired functional groups. The structural, compositional, morphological and magnetic analyzes of the prepared samples were carried out using various characterization techniques. The fabricated rGO/Fe2O3 heterostructures were confirmed by X-ray diffraction analysis and Fourier transform infrared spectroscopy. Raman spectroscopy evidenced the fabrication of multilayer graphene and scanning electron microscopy was carried out to study the morphology of the prepared samples. The average particle size of Fe2O3 nanoparticles (NPs) loaded on rGO was found to be [Formula: see text]20 nm, as was observed during transmission electron microscopy. Thermogravimetric analysis of rGO/Fe2O3 hybrid structures was performed to investigate their thermal behaviors. It was evidenced that the incorporation of Fe2O3 NPs into rGO enhanced its thermal stability. Vibrating sample magnetometry showed that ferromagnetic character was induced in rGO due to involvement of Fe2O3 NPs. The rGO/Fe2O3 hybrid structures can be considered as a competent material for fabrication of various magnetic devices.

Preparation and Application of Palladium Nanoparticle Impregnated Chloromethylated Polysulfone Matrix as an Efficient Catalytic Membrane for Oxidation of Alcohols

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hossein Mahdavi ◽  
Faeze Fayyazi
Keyword(s):  
Chemical Structure ◽  
Average Particle Size ◽  
Pd Nanoparticles ◽  
Significant Loss ◽  
Average Particle ◽  
Catalytic Membranes ◽  
Solvent Free Condition ◽  
Oxidation Of Alcohols ◽  
20 Nm ◽  
Tga And Dsc

AbstractThe use of palladium nanoparticles embedded in a chloromethylated Polysulfone (CMPSf) matrix was developed for highly efficient oxidation of primary and secondary alcohols to corresponding aldehyde and ketone in organic solvent free condition. Pd (Π)/bis (2, 4-dihydroxybenzaldehyde) chelate chemically incorporated onto CMPSf was used to prepare beneficial catalytic membranes. Chemical structure and thermal properties of resulting membranes were characterized via FTIR, 1HNMR, UV-vis, TGA and DSC techniques. Morphology and particle distribution throughout the catalytic membranes was elucidated using FE-SEM. An average particle size of Pd nanoparticles was estimated about 20 nm by XRD technique. ICP technique proved that no Pd particles were leached out of the membrane into the solutions; hence the as-prepared catalytic membranes could be used several times without significant loss in their activities. This is in good accordance with formation of chemical bond between Pd and polymer matrix.

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