scholarly journals Gas Sensing Properties and Mechanism of Nano-SnO2-Based Sensor for Hydrogen and Carbon Monoxide

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Weigen Chen ◽  
Qu Zhou ◽  
Fu Wan ◽  
Tuoyu Gao
Keyword(s):  
Carbon Monoxide ◽  
Adsorption Process ◽  
Gas Sensing ◽  
Power Transformer ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Molecule ◽  
Gas Sensing Properties ◽  
Transformer Fault ◽  
Optimum Working

Nano-SnO2powder was prepared by the hydrothermal method in this paper. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the composition of the crystalline phase and the morphology of the prepared gas-sensitive materials, respectively. In particular, the study focused on the sensing behaviors of nano-SnO2-based sensor towards power transformer fault gases such as hydrogen and carbon monoxide. The optimum working temperature for hydrogen and carbon monoxide is about 400∘C and 360∘C, separately. Further investigations into the adsorption process of gas molecule on SnO2(110) surface based on the first principles were conducted. The calculations indicated that 1σorbits of H2split into several new electronic peaks and 5σorbits of CO almost degenerated completely in the adsorption process, which promoted charge transfer between gas molecule and SnO2(110) surface. It provides a qualitative explanation for the prepared nano-SnO2-based sensor exhibiting different gas sensing properties towards H2and CO.

scholarly journals Hydrothermal Synthesis of Pt-, Fe-, and Zn-dopedSnO2Nanospheres and Carbon Monoxide Sensing Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Weigen Chen ◽  
Qu Zhou ◽  
Shudi Peng
Keyword(s):  
Carbon Monoxide ◽  
Gas Sensing ◽  
First Principles Calculation ◽  
Diffraction Field ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Response And Recovery ◽  
Higher Sensitivity

Pure and M-doped (M = Pt, Fe, and Zn) SnO2nanospheres were successfully synthesized via a simple and facile hydrothermal method and characterized by X-ray powder diffraction, field-emission scanning electron microscopy, and energy dispersive spectroscopy. Chemical gas sensors were fabricated based on the as-synthesized nanostructures, and carbon monoxide sensing properties were systematically measured. Compared to pure, Fe-, and Zn-doped SnO2nanospheres, the Pt-doped SnO2nanospheres sensor exhibits higher sensitivity, lower operating temperature, more rapid response and recovery, better stability, and excellent selectivity. In addition, a theoretical study based on the first principles calculation was conducted. All results demonstrate the potential of Pt dopant for improving the gas sensing properties of SnO2-based sensors to carbon monoxide.

scholarly journals Preparation of Nanostructured SnO2-NiO Composite Semiconductor for Gas Sensor Applications

2021 ◽  
pp. 391-403
Author(s):  
S. Kumar ◽  
P. Gowthaman ◽  
J. Deenathayalan
Keyword(s):  
Gas Sensor ◽  
Composite Nanofibers ◽  
Volume Fraction ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Response Sensitivity ◽  
X Ray ◽  
Sensing Properties ◽  
Working Temperature ◽  
Gas Sensing Properties

Electro spinning technology combined with chemical precipitation method and high-temperature calcination was used to prepare SnO2-NiO composite semiconductor nanofibers with different Sn content. Scanning electron microscope (SEM), X-ray diffractometer (XRD) and energy dispersive X-ray spectrometer (EDS) were used to characterize the morphology, structure and content of various elements of the sample. Using ethanol as the target gas, the gas sensing properties of SnO2-NiO nanofibers and the influence of Sn content on the gas sensing properties of composite nanofibers were explored. The research results show that SnO2-NiO composite nanofibers have a three-dimensional network structure, and the SnO2 composite can significantly enhance the gas sensitivity of NiO nanofibers. With increase of SnO2 content, the response sensitivity of composite fibers to ethanol gas increases, and the response sensitivity of composite nanofibers with the highest response to ethanol gas with a volume fraction of 100×10-6 at the optimal working temperature of 160℃ are13.4;It is 8.38 times the maximum response sensitivity of NiO nanofibers. Compared with the common ethanol gas sensor MQ-3 on the market, SnO2-NiO composite nanofibers have a lower optimal working temperature and higher response sensitivity, which has certain practical application value

Carbon monoxide gas-sensing properties of CeO2–WO3thin films

2010 ◽  
Vol 26 (6) ◽  
pp. 726-731 ◽  
Author(s):  
M. F. Al-Kuhaili ◽  
S. M. A. Durrani ◽  
I. A. Bakhtiari
Keyword(s):  
Carbon Monoxide ◽  
Gas Sensing ◽  
Sensing Properties ◽  
Gas Sensing Properties

Synthesis and Gas Sensing Properties of SnO2 Nanostructures by Thermal Evaporation

2012 ◽  
Vol 620 ◽  
pp. 350-355 ◽  
Author(s):  
Wan Normiza Wan Mustapha ◽  
S.A. Rezan Sheikh Abdul Hamid ◽  
Sabar Derita Hutagalung ◽  
Nguyen Van Hieu ◽  
Khairudin Mohamed ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Thermal Evaporation ◽  
Gas Sensing ◽  
Oxide Phase ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Sensing Properties ◽  
Synthesis Conditions ◽  
Gas Sensing Properties ◽  
Size And Morphology

Tin oxide nanostructures (NS) were grown on silicon substrates by thermal evaporation method with three different parameters. These parameters were temperatures (650 °C, 750 °C and 850 °C), nickel catalyst concentrations (0, 5 and 10 milimoles) and tin powder source to substrate distances (2 cm, 4 cm and 6 cm). The parameters were found to affect the size and morphology of the synthesized nanostructures. Formation of nanospheres (NSs), nanoneedles (NNs) and nanowires (NWs) of tin oxide were observed by Scanning Electron Microscope (SEM) at different synthesis conditions. Synthesis temperature was found to have most pronounced effect on the size and morphology of the nanostructures. Catalyst concentration has affected the porosity and growth of the nanostructures. The distance between source and substrate affected the nanostructures predominately on distribution and particle size. Energy dispersion X-ray (EDX) analysis confirms the presence of tin and oxygen in all nanostructures at all synthesis conditions. X-ray diffraction (XRD) proves the formation of tin oxide phase in all samples. Significant formation of tin oxide nanowires was observed at 850 °C. Gas sensing properties of SnO2 nanowires (NW) toward ethanol (C2H5OH) gas at 450°C with different volume concentration was measured. It was found SnO2 NW had good sensing properties for C2H5OH at 100 ppm compared to measurements made at 25-50 ppm.

Carbon monoxide gas-sensing properties of CeO2–ZnO thin films

2008 ◽  
Vol 255 (5) ◽  
pp. 3033-3039 ◽  
Author(s):  
M.F. Al-Kuhaili ◽  
S.M.A. Durrani ◽  
I.A. Bakhtiari
Keyword(s):  
Thin Films ◽  
Carbon Monoxide ◽  
Gas Sensing ◽  
Zno Thin Films ◽  
Sensing Properties ◽  
Gas Sensing Properties

Effect of Au Doped WO3 Gas Sensors for NO2 Detection

2011 ◽  
Vol 492 ◽  
pp. 308-311 ◽  
Author(s):  
Wu Bin Gao ◽  
Cheng Dong ◽  
Xu Liu ◽  
Yun Han Ling ◽  
Jia Lin Sun
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Point Contact ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Tungsten Filaments ◽  
Gas Response ◽  
Contact Sensors

Gas sensor based on point contact tungsten trioxide (WO3) was prepared by in-situ induction-heating thermal oxidation of tungsten filaments. X-ray diffractometry (XRD) and field emission scanning electron microscopy (FESEM) were employed to analyze the phase and the morphology of the fabricated thin films. The results showed that the WO3films exhibited a monoclinic phase and were composed of hierarchical micro and nano crystals. The NO2(1-8 ppm) sensing properties of the point contact sensors based on Pure and Au-sputtering doped (2.5 at%) WO3films were investigated. The results showed that the gas sensing properties of the Au (2.5 at%) doped WO3sensors were superior to those of the undoped. The obtained point contact WO3sensor exhibited the maximum NO2gas response at 100°C.

scholarly journals Characterization and Optical Gas Sensing Properties of BaSnO3 Synthesized By Novel Technique: Flame Spray Pyrolysis

2021 ◽  
Author(s):  
Merve ZEYREK ONGUN ◽  
Sibel OGUZLAR ◽  
Alper S. Akalin ◽  
Serdar Yildirim
Keyword(s):  
Spray Pyrolysis ◽  
Photoelectron Spectroscopy ◽  
Near Infrared ◽  
Gas Sensing ◽  
Flame Spray Pyrolysis ◽  
Electromagnetic Spectrum ◽  
Flame Spray ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties

Abstract Barium stannate (BaSnO3) particles were synthesized using a one-step flame spray pyrolysis (FSP) method. The fabricated ceramic powders were investigated in terms of the structural, morphological, and optical properties by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-Ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), zeta particle size analyzer, UV-visible spectroscopy (UV-vis) and photoluminescence spectroscopy (PL). The XRD results showed the structure of BaSnO3 crystals have been obtained when the powders were exposed at high temperature, specifically at 1200 °C. The synthesized particles in the submicron size in a range of 70-980 nm were produced. The optical band gap value of the synthesized crystals was calculated by means of reflectance spectra with the Kubelka-Munk method and found as 3.14 eV. When the powders excited at 375 nm, they exhibited emission bands in the visible and near-infrared region (NIR) of the electromagnetic spectrum. As far as we know, this is the first time BaSnO3 crystals have been synthesized using the FSP technique. In this study, the intensity- and decay time- based gas sensing properties of BaSnO3 embedded in ethyl cellulose thin films when exposed to the vapors of ethanol, acetone, and ammonia were also measured.

Synthesis of Al Doped ZnO with a Novel Rice Microstructure by Hydrothermal Process and Analysis of their Gas Sensing Properties

2014 ◽  
Vol 809-810 ◽  
pp. 724-730
Author(s):  
Zan Li ◽  
Wei Qin ◽  
Xiao Hong Wu
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Hexagonal Wurtzite Structure ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Doped Zno ◽  
Hydrothermal Approach

Al-doped ZnO (AZO) powers with a novel rice-like morphology have been successfully synthesized through a simple and efficient hydrothermal approach, the products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray analyzer and transmission electron microscopy (TEM). It showed that all the samples presented an hexagonal wurtzite structure of high crystallinity, and the microstructure was composed of numerous dumbbells. Furthermore, the heater gas sensors were fabricated and an investigation of gas sensing properties has been conducted. The sensors showed good selectivity to ethanol comparing with NH3, SO2, CO and HCHO and possible mechanism was discussed. The Sensors based AZO powers exhibited high response values, reproducible response-recovery to ethanol 50-1800 ppm at 332°C.

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