Polyaniline/SnO2 Nanocomposite Sensor for NO2 Gas Sensing at Low Operating Temperature

2015 ◽  
Vol 14 (04) ◽  
pp. 1550011 ◽  
Author(s):  
A. Sharma ◽  
M. Tomar ◽  
V. Gupta ◽  
A. Badola ◽  
N. Goswami
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
Sensing Properties ◽  
Response Recovery ◽  
Transmission Electron ◽  
Gas Sensing Properties

In this paper gas sensing properties of 0.5–3% polyaniline (PAni) doped SnO 2 thin films sensors prepared by chemical route have been studied towards the trace level detection of NO 2 gas. The structural, optical and surface morphological properties of the PAni doped SnO 2 thin films were investigated by performing X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Raman spectroscopy measurements. A good correlation has been identified between the microstructural and gas sensing properties of these prepared sensors. Out of these films, 1% PAni doped SnO 2 sensor showed high sensitivity towards NO 2 gas along with a sensitivity of 3.01 × 102 at 40°C for 10 ppm of gas. On exposure to NO 2 gas, resistance of all sensors increased to a large extent, even greater than three orders of magnitude. These changes in resistance upon removal of NO 2 gas are found to be reversible in nature and the prepared composite film sensors showed good sensitivity with relatively faster response/recovery speeds.

scholarly journals Chemically synthesized PbS Nano particulate thin films for a rapid NO2 gas sensor

2016 ◽  
Vol 34 (1) ◽  
pp. 204-211 ◽  
Author(s):  
Vishal V. Burungale ◽  
Rupesh S. Devan ◽  
Sachin A. Pawar ◽  
Namdev S. Harale ◽  
Vithoba L. Patil ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Sensor ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
Silar Method ◽  
Layer Adsorption ◽  
Gas Sensing Properties

AbstractRapid NO2 gas sensor has been developed based on PbS nanoparticulate thin films synthesized by Successive Ionic Layer Adsorption and Reaction (SILAR) method at different precursor concentrations. The structural and morphological properties were investigated by means of X-ray diffraction and field emission scanning electron microscope. NO2 gas sensing properties of PbS thin films deposited at different concentrations were tested. PbS film with 0.25 M precursor concentration showed the highest sensitivity. In order to optimize the operating temperature, the sensitivity of the sensor to 50 ppm NO2 gas was measured at different operating temperatures, from 50 to 200 °C. The gas sensitivity increased with an increase in operating temperature and achieved the maximum value at 150 °C, followed by a decrease in sensitivity with further increase of the operating temperature. The sensitivity was about 35 % for 50 ppm NO2 at 150 °C with rapid response time of 6 s. T90 and T10 recovery time was 97 s at this gas concentration.

A Formaldehyde Gas Sensor Based on Zinc Doped Lanthanum Ferrite

2013 ◽  
Vol 873 ◽  
pp. 304-310 ◽  
Author(s):  
Jin Zhang ◽  
Yu Min Zhang ◽  
Chang Yi Hu ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Lanthanum Ferrite ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Sensing Characteristics

The gas-sensing properties of zinc doped lanthanum ferrite (Zn-LaFeO3) compounds for formaldehyde were investigated in this paper. Zn-LaFeO3 powders were prepared using sol-gel method combined with microwave chemical synthesis. The powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The formaldehyde gas-sensing characteristics for the sample were examined. The experimental results indicate that the sensor based on the sample Zn-LaFeO3 shows excellent gas-sensing properties to formaldehyde gas. At the optimal operating temperature of 250°C, the sensitivity of the sensor based on LaFe0.7Zn0.3O3 to 100ppm formaldehyde is 38, while to other test gases, the sensitivity is all lower than 20. The response and recovery times for the sample to formaldehyde gas are 100s and 100s, respectively.

Au-sensitized WO3 nanoparticles synthesized and their enhanced acetone sensing properties

2018 ◽  
Vol 11 (04) ◽  
pp. 1850071 ◽  
Author(s):  
Dongping Xue ◽  
Zhanying Zhang
Keyword(s):  
Recovery Time ◽  
Gas Sensing ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Response Recovery ◽  
Two Samples ◽  
Gas Sensing Properties ◽  
Scanning Electron

Au-sensitized WO3 nanoparticles have been synthesized by a facile two-step hydrothermal method. The structures, morphologies and surface compositions of the materials were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The test results show that we have prepared higher purity Au-sensitized WO3 nanoparticles. The gas-sensing properties of pure and Au-sensitized WO3 nanoparticles on acetone vapor were further investigated. The results obtained show that the response-recovery time of the two samples prepared is relatively short compared to that reported in the current literature. The Au-sensitized WO3 nanoparticles are significantly more sensitive and selective than the pure WO3 nanoparticles. This may be mainly attributed to the synergy between Au and WO3. It is expected that the Au-sensitized WO3 nanoparticles thus prepared can also be used for research in other fields.

scholarly journals Synthesis of Hollow ZnSnO3 Nanospheres with High Ethanol Sensing Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Qiong Wang ◽  
Na Yao ◽  
Chen Liu ◽  
Dongmin An ◽  
Yan Li ◽  
...  
Keyword(s):  
Gas Sensing ◽  
High Sensitivity ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Surface Areas ◽  
Transmission Electron ◽  
Hollow Nanostructures ◽  
Response And Recovery ◽  
Ethanol Sensing

Hollow ZnSnO3 nanospheres were synthesized by a hydrothermal method using ZnO nanospheres as the hard template and raw material simultaneously. The combined characterizations of X-ray diffraction (XRD), scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HRTEM) confirmed the successful preparation of hollow ZnSnO3 nanospheres. The gas-sensing results indicated that the sensor made from hollow ZnSnO3 nanospheres exhibited high sensitivity, good selectivity, and stability to ethanol at a low operating temperature of 200°C. The sensitivity was about 32 and the response and recovery time were about 4 s and 30 s for 100 ppm ethanol, respectively. The enhancement in gas-sensing properties was attributed to the hollow nanostructures and high specific surface areas of ZnSnO3.

Low-Temperature Synthesis and Gas Sensing Properties of Anatase TiO2 Thin Films

2011 ◽  
Vol 492 ◽  
pp. 300-303
Author(s):  
Fu Jian Ren ◽  
Yi Sun ◽  
Liang Huang ◽  
Yun Han Ling ◽  
Jia You Feng
Keyword(s):  
Thin Films ◽  
Deposition Temperature ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Gas Sensing Properties ◽  
Gas Response

Crystalline anatase TiO2thin films were obtained on glass substrates at 60°C, 75°C and 90°C, respectively, by liquid phase deposition (LPD) method without subsequent heat treatment. X-ray diffraction (XRD), atomic force microscopy (AFM) and UV-Vis spectrophotometer were used to characterize the as-synthesized TiO2thin films. The H2sensing properties of the TiO2thin films based sensors were investigated. The results show that the gas sensors signal Ra/Rg (Ra: resistance in air, Rg: resistance in a sample gas) decreases with the increasing deposition temperature. The TiO2thin films obtained at deposition temperature of 60°C exhibited the maximum H2gas response at 350°C, and the magnitude of the sensor signal and the response time for 500ppm H2was 1.25 and 17s, respectively.

Annealing Temperature Dependent on Microstructure and Ethanol Gas Sensing Properties of TiO2Thin Films

2013 ◽  
Vol 770 ◽  
pp. 213-216
Author(s):  
Benjarong Samransuksamer ◽  
Worawarong Rakreungdet ◽  
Supattanapong Dumrongrattana ◽  
M. Horprathum ◽  
Pitak Eiamchai ◽  
...  
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Gas Sensing ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Sensing Properties ◽  
Dc Reactive Magnetron Sputtering ◽  
Gas Sensing Properties ◽  
Microstructure Morphology ◽  
Deposited Films

The TiO2 thin films were prepared by a dc reactive magnetron sputtering technique from high purity Ti target on silicon (100) wafers and alumina substrates inter-digital with gold electrodes. The as-deposited films were annealed from 400°C up to 800°C with 100 °C steps for 1 hour in air ambience in order to promote microstructure, morphology and gas-sensing properties. The change in microstructure and morphology of the films were investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The enhancement in the gas-sensing properties was test by ethanol gas. The prepared thin films were exposed to ethanol gas at concentration 1,000 ppm in purify dry air carrier. The resistance was measured as a function of the ethanol concentration of the films at operated temperatures in the range of 250 - 350°C. The influence of annealing temperature at 500 °C of TiO2 thin film has a highest sensitivity at 350 °C operated temperature.

The Microwave-Assisted Synthesis and Gas Sensing Properties for Ethanol of SnO2 Nanomaterials

2013 ◽  
Vol 721 ◽  
pp. 237-240 ◽  
Author(s):  
Yong Ju Liu ◽  
Qiu Ping Jiang ◽  
Yue Huan Li ◽  
He Yun Zhao
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Good Crystalline Quality ◽  
Gas Sensing Properties ◽  
Microwave Assisted Method

With the advantages of the microwave-assisted method, good crystalline quality SnO2nanomaterials were successfully synthesized. The morphology and microstructure of SnO2were characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy and high-resolution (HRTEM) used to examine SnO2nanomaterials. Indirect-heating sensors based on nanorods were fabricated and investigated for the gas sensing properties to ethanol. The investigation demonstrates that the sensor based on prepared SnO2nanomaterials has good sensitivity, low detection limit and short response and reversion time to ethanol at 275 °C.

The Characterization and Gas Sensing Properties of Polythiophene Coated V2O5 Nanotubes

2010 ◽  
Vol 654-656 ◽  
pp. 1154-1157 ◽  
Author(s):  
Yu Lu ◽  
Wei Jin ◽  
Wen Chen
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Higher Sensitivity

Polythiophene (PTP) coated V2O5 nanotubes were prepared by an in-situ polymerization of thiophene monomers in the presence of prepared V2O5 nanotubes. The nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which proved the polymerization of thiophene monomer and the strong interaction between polythiophene and V2O5 nanotubes (VONTs). The gas sensing properties of PTP coated V2O5 nanotubes were studied at room temperature, which was found that PTP coated V2O5 nanotubes could detect ethanol with much higher sensitivity than pure VONTs. The sensing mechanism of PTP coated V2O5 nanotubes to ethanol is presumed to be the synergetic interaction between polythiophene (PTP) and V2O5 nanotubes.

scholarly journals Synthesis by Thermal Oxidation and Gas Sensing Properties of Fe2O3 Nanorods

2021 ◽  
Vol 31.2 (149) ◽  
pp. 84-88
Keyword(s):  
Thermal Oxidation ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Measuring System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sensing Properties ◽  
Oxide Nanorods ◽  
Gas Sensing Properties ◽  
Sensitivity And Selectivity

Iron oxide nanorods were synthesized by thermal oxidation of iron foil in the air at 300-500 oC. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to investigate the crystal structures and morphologies properties of the Fe2O3 nanorods. The gas sensing properties of the Fe2O3 nanorods were investigated using a static-gas measuring system in a range of 300-500 oC with the target gases of C2H5OH, CH3COCH3, LPG, and NH3. The results show that Fe2O3 nanorods possess high sensitivity and selectivity toward CH3COCH3. The highest response of 19 was recorded with 1000 ppm CH3COCH3 at the operating temperature of 400 oC.

Oxygen vacancies-contained SnO2 nanotubes with enhanced ethanol gas sensing properties

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040003 ◽  
Author(s):  
Yifan Chen ◽  
Xiuling Ma ◽  
Chen Li ◽  
Qiuyu Wu ◽  
Yongbo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Performance ◽  
Oxygen Vacancies ◽  
Gas Sensing ◽  
Original Sample ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Ethanol Sensing

[Formula: see text] porous nanotubes containing oxygen vacancies were prepared by electron spinning and H plasma treatment. The morphology and crystal structure of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The ethanol-sensing properties of the [Formula: see text] sensor were tested. The results show that the samples treated with H plasma for 20 min have the best performance. Its working temperature is [Formula: see text]C lower than [Formula: see text]C of the original sample, with a sensitivity of 17 at 100 ppm, which is seven times higher than the original sample. It also shows good selectivity to some common interfering gases. This enhancement can be ascribed to the introduced oxygen vacancy. This work provides an efficient way to design high-performance gas sensor materials.

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