scholarly journals Research on Acetylene Sensing Properties and Mechanism of SnO2Based Chemical Gas Sensor Decorated with Sm2O3

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Qu Zhou ◽  
Meiqing Cao ◽  
Wude Li ◽  
Chao Tang ◽  
Shiping Zhu
Keyword(s):  
Gas Sensing ◽  
Power Transformer ◽  
Transformer Oil ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Hydrocarbon Gases ◽  
Promising Candidate ◽  
Analysis System ◽  
Fault Characteristic

Acetylene C2H2gas is one of the most important fault characteristic hydrocarbon gases dissolved in oil immersed power transformer oil. This paper reports the successful preparation and characterization of samarium oxide Sm2O3decorated tin oxide SnO2based sensors with hierarchical rod structure for C2H2gas detection. Pure and Sm2O3decorated SnO2sensing structures were synthesized by a facile hydrothermal method and characterized by XRD, FESEM, TEM, EDS, and XPS measurements, respectively. Planar chemical gas sensors with the synthesis samples were fabricated, and their sensing performances to C2H2gas were systematically performed and automatically recorded by a CGS-1 TP intelligent gas sensing analysis system. The optimum operating temperature of the Sm2O3decorated SnO2based sensor towards 50 μL/L of C2H2is 260°C, and its corresponding response value is 38.12, which is 6 times larger than the pure one. Its response time is about 8–10 s and 10–13 s for recovery time. Meanwhile good stability and reproducibility of the decorated sensor to C2H2gas are also obtained. Furthermore, the proposed sensor exhibits excellent C2H2selectivity among some potential interface gases, like H2and CO gas. All sensing results indicate the sensor fabricated with oxide Sm2O3decorated SnO2nanorods might be a promising candidate for C2H2detection in practice.

SnO2 Nanofibers Gas Sensor Detecting H2 Dissolved in Transformer Oil

2013 ◽  
Vol 706-708 ◽  
pp. 1008-1011
Author(s):  
Shu Di Peng ◽  
Gao Lin Wu ◽  
Qian Wang
Keyword(s):  
Gas Sensor ◽  
Gas Sensing ◽  
Power Transformer ◽  
Synthesis Method ◽  
Transformer Oil ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Fault Gas ◽  
Response And Recovery ◽  
Hydrothermal Approach

Hydrogen is an effective fault gas dissolved in transformer oil, and online monitoring its concentration has important meaning on condition assessment and fault diagnosis of power transformer. A facile and simple synthesis method of ultra-sensitive SnO2nanofibers through a hydrothermal approach was reported. The crystalline phases and microstructures were performed by X-ray powder diffraction and field-emission scanning electron microscopy. The gas sensor based on prepared SnO2 nanofibers was fabricated by a side-heated preparation, and its gas sensing performances to H2were measured. The fabricated sensor exhibits excellent sensing properties to H2, such as low optimum operating temperature, high gas response, rapid response and recovery time, good stability and repeatability.

scholarly journals Pd-Doped SnO2-Based Sensor Detecting Characteristic Fault Hydrocarbon Gases in Transformer Oil

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Weigen Chen ◽  
Qu Zhou ◽  
Tuoyu Gao ◽  
Xiaoping Su ◽  
Fu Wan
Keyword(s):  
Molecular Orbital ◽  
Online Monitoring ◽  
Gas Sensing ◽  
Power Transformer ◽  
Transformer Oil ◽  
Orbital Energy ◽  
Hydrocarbon Gases ◽  
X Ray ◽  
Molecular Orbital Energy ◽  
Highest Occupied Molecular Orbital

Methane (CH4), ethane (C2H6), ethylene (C2H4), and acetylene (C2C2) are important fault characteristic hydrocarbon gases dissolved in power transformer oil. Online monitoring these gaseous components and their generation rates can present the operational state of power transformer timely and effectively. Gas sensing technology is the most sticky and tricky point in online monitoring system. In this paper, pure and Pd-doped SnO2nanoparticles were synthesized by hydrothermal method and characterized by X-ray powder diffraction, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The gas sensors were fabricated by side-heated preparation, and their gas sensing properties against CH4, C2H6, C2H4, and C2H2were measured. Pd doping increases the electric conductance of the prepared SnO2sensors and improves their gas sensing performances to hydrocarbon gases. In addition based on the frontier molecular orbital theory, the highest occupied molecular orbital energy and the lowest unoccupied molecular orbital energy were calculated. Calculation results demonstrate that C2H4has the highest occupied molecular orbital energy among CH4, C2H6, C2H4, and C2H2, which promotes charge transfer in gas sensing process, and SnO2surfaces capture a relatively larger amount of electric charge from adsorbed C2H4.

Xylene-sensing of Fe2(MoO4)3 nanoplates prepared via a hydrothermal method

2017 ◽  
Vol 10 (03) ◽  
pp. 1750022 ◽  
Author(s):  
Mengying Xu ◽  
Zhidong Lin ◽  
Wenying Guo ◽  
Yuyuan Hong ◽  
Ping Fu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Hydrothermal Process ◽  
Optimum Operating ◽  
Average Crystalline Size ◽  
Optimum Operating Temperature ◽  
Recovery Times ◽  
Response And Recovery ◽  
Simple Hydrothermal Process

Fe2(MoO4)3 nanoplates were prepared via a simple hydrothermal process. The average crystalline size of these nanoplates is 85.8[Formula: see text]nm. The sensor based on Fe2(MoO4)3 shows a high gas sensing performance to xylene. The response of Fe2(MoO4)3 sensor is 25.9–100[Formula: see text]ppm xylene at optimum operating temperature of 340[Formula: see text]C. The response and recovery times to 100[Formula: see text]ppm xylene are 4 and 10[Formula: see text]s, respectively. Furthermore, the Fe2(MoO4)3 sensor exhibits remarkable selectivity detection of xylene gas with negligible responses to toluene and benzene. Therefore, the Fe2(MoO4)3 is a promising material for the detection of xylene gas sensors.

TUNGSTEN-DOPED TiO2 NANOLAYERS WITH IMPROVED CO2 GAS SENSING PROPERTIES FOR ENVIRONMENTAL APPLICATIONS

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850024 ◽  
Author(s):  
MALIHEH SABERI ◽  
ALI AKBAR ASHKARRAN
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Sol Gel ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Vis Spectroscopy ◽  
Gas Sensing Properties ◽  
Tungsten Concentration

Tungsten-doped TiO2 gas sensors were successfully synthesized using sol–gel process and spin coating technique. The fabricated sensor was characterized by field emission scanning electron microscopy (FE-SEM), ultraviolet visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Gas sensing properties of pristine and tungsten-doped TiO2 nanolayers (NLs) were probed by detection of CO2 gas. A series of experiments were conducted in order to find the optimum operating temperature of the prepared sensors and also the optimum value of tungsten concentration in TiO2 matrix. It was found that introducing tungsten into the TiO2 matrix enhanced the gas sensing performance. The maximum response was found to be (1.37) for 0.001[Formula: see text]g tungsten-doped TiO2 NLs at 200[Formula: see text]C as an optimum operating temperature.

scholarly journals Enhanced Methane Sensing Properties of WO3 Nanosheets with Dominant Exposed (200) Facet via Loading of SnO2 Nanoparticles

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 351 ◽  
Author(s):  
Dongping Xue ◽  
Junjun Wang ◽  
Yan Wang ◽  
Guang Sun ◽  
Jianliang Cao ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Defect Density ◽  
Sno2 Nanoparticles ◽  
High Reactivity ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Subsequent Calcination

Methane detection is extremely difficult, especially at low temperatures, due to its high chemical stability. Here, WO3 nanosheets loaded with SnO2 nanoparticles with a particle size of about 2 nm were prepared by simple impregnation and subsequent calcination using SnO2 and WO3·H2O as precursors. The response of SnO2-loaded WO3 nanosheet composites to methane is about 1.4 times higher than that of pure WO3 at the low optimum operating temperature (90 °C). Satisfying repeatability and long-term stability are ensured. The dominant exposed (200) crystal plane of WO3 nanosheets has a good balance between easy oxygen chemisorption and high reactivity at the dangling bonds of W atoms, beneficial for gas-sensing properties. Moreover, the formation of a n–n type heterojunction at the SnO2-WO3 interface and additionally the increase of specific surface area and defect density via SnO2 loading enhance the response further. Therefore, the SnO2-WO3 composite is promising for the development of sensor devices to methane.

Transformer Mineral Oil Mixtures Characterization by Isothermal Charging Currents

2013 ◽  
Vol 664 ◽  
pp. 632-637
Author(s):  
Tahar Toudja ◽  
Hocine Moulai ◽  
Azzeddine Nacer ◽  
Abdeslem Beldjillali ◽  
Nadia Saidi ◽  
...  
Keyword(s):  
Power Transformer ◽  
Physicochemical Characteristics ◽  
Field Application ◽  
Transformer Oil ◽  
Oil Mixtures ◽  
Physicochemical Methods ◽  
High Voltage Insulation ◽  
Solid Dielectrics ◽  
Good Agreement

This work aims at the characterization of power transformer oil mixtures by using dc charging currents measurements for long field application times. The principle of this approach is inspired from the technique of measurements carried out on solid dielectrics used in high voltage insulation. It will be applied to characterize mixtures between two compatible oils of different provenances and ages. The obtained results are conclusive and reinforce those obtained by classical physicochemical methods of characterization. For the purpose, we intent to link between the space charge behavior in the insulation and its several characteristics. Moreover, in addition to the fact that the obtained results are in good agreement with the physicochemical characteristics, the charging currents reported at room temperature enabled us to determine the mixture resistivity and charge carriers' mobility.

A Novel Ceramic Sensing Material for Acetone Detection from Asphalt

2021 ◽  
Vol 16 (2) ◽  
pp. 312-317
Author(s):  
Peng Duan ◽  
Chunli Zhang ◽  
Wusi Chen ◽  
Yan Fu
Keyword(s):  
Electron Microscope ◽  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Optimum Operating ◽  
Acetone Vapor ◽  
X Ray Diffraction ◽  
Optimum Operating Temperature ◽  
Sensing Material ◽  
Transmission Electron ◽  
Acetone Detection

A novel ceramic sensing material, orthorhombic molybdenum trioxide (a-MoO3) nanobelts, was successfully prepared through a simple hydrothermal strategy. And its crystalline phase and microstructures were characterized via X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The results indicate that the size of the a-MoO3 nanobeltsis 180-250 nm in width and several microns in length. Gas sensing performances of the as-synthesized a-MoO3 nanobelts towards acetone vapor which was a representative VOCs in asphalt were investigated. The a-MoO3 nanobelts based gas sensor exhibits superior response at the optimum operating temperature of 300 °C for 200 ppm acetone vapor and excellent stability. The gas sensing mechanism for the a-MoO3 nanobelts to acetone vapor was also discussed.

scholarly journals Prediction of Gas Dissolved in Power Transformer Oil by Non-equidistant Multivariable Grey Model

2018 ◽  
Vol 173 ◽  
pp. 01009
Author(s):  
Sun Na ◽  
Liang Ling Tao
Keyword(s):  
Power Systems ◽  
Power Transformer ◽  
Transformer Oil ◽  
Grey Model ◽  
Grey Theory ◽  
Comparison Result ◽  
Proposed Model ◽  
Scope Of Application ◽  
Concentration Prediction ◽  
Fault Characteristic

Power transformer is an essential component in the power systems. The concentration of fault characteristic gases dissolved transformer oil is essential to the insulation fault diagnosis. The concentration prediction of the gases is an important supplement for periodical testing. A NMGM(1, 5)model using Nou-equidistance Multivariable grey theory for the five characteristic gases dissolved in transformer oil, i.e. hydrogen, methane, ethane, ethylene, acetylene, was constructed. In the built model, the interaction among these gases was comprehensively considered and the disadvantage that only one index extracted from the signal or each index that was dealt with separately was made up, meanwhile, the scope of application is enlarged. Two actual prediction cases were analyzed and the results were compared with those obtained by Non-equidistant GM(1, l)model. The comparison result indicates the validity and efficiency of the proposed model.

scholarly journals Hydrothermal Synthesis and Structural Characterization of NiO/SnO2Composites and Hydrogen Sensing Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Chao Wei ◽  
Bin Bo ◽  
Fengbo Tao ◽  
Yuncai Lu ◽  
Shudi Peng ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Power Transformer ◽  
Transformer Oil ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Hydrogen Sensing ◽  
Sensing Material ◽  
P Type ◽  
Surface Morphologies ◽  
Gas Response

Pure SnO2and NiO doped SnO2nanostructures were successfully synthesized via a simple and environment-friendly hydrothermal method. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectra (XPS) were used to investigate the crystalline structures, surface morphologies and microstructures, and element components and their valences of the as-synthesized samples. Furthermore, planar chemical gas sensors based on the synthesized pure SnO2and NiO/SnO2composites were fabricated and their sensing performances to hydrogen, an important fault characteristic gas dissolved in power transformer oil, were investigated in detail. Gas sensing experiments indicate that the NiO/SnO2composites showed much higher gas response and lower working temperature than those of pure SnO2, which could be ascribed to the formation of p-n heterojunctions between p-type NiO and n-type SnO2. These results demonstrate that the as-synthesized NiO/SnO2composites a promising hydrogen sensing material.

scholarly journals Nano Ag-DopedIn2O3Thick Film: A Low-TemperatureH2SGas Sensor

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
D. N. Chavan ◽  
G. E. Patil ◽  
D. D. Kajale ◽  
V. B. Gaikwad ◽  
P. K. Khanna ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Thick Films ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Ethanol Vapour ◽  
Nano Silver ◽  
Sensitivity And Selectivity ◽  
Response And Recovery ◽  
Surface Modified ◽  
Sensing Performance

Thick films of AR grade In2O3were prepared by standard screen-printing technique. The gas sensing performances of thick films were tested for various gases. It showed maximum sensitivity to ethanol vapour at 350°C for 80 ppm concentration. To improve the sensitivity and selectivity of the film towards a particular gas, In2O3sensors were surface-modified by dipping them in a solution of 2% nanosilver for different intervals of time. Obtained results indicated that spherical nano-Ag grains are highly dispersed on the surface of In2O3sensor. The surface area of the nano-Ag/ In2O3sensor is several times larger than that of pure In2O3sensor. In comparison with pure In2O3sensor, all of the nano-Ag-doped sensors showed better sensing performance in respect of response, selectivity, and optimum operating temperature. The surface-modified (30 min) In2O3sensor showed larger sensitivity to H2S gas (10 ppm) at 100°C. Nano silver on the surface of the film shifts the reactivity of film from ethanol vapour to H2S gas. A systematic study of gas sensing performance of the sensor indicates the key role played by the nano silver species on the surface. The sensitivity, selectivity, response, and recovery time of the sensor were measured and presented.

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