scholarly journals Effects of sintering temperature on sensing properties of WO 3 and Ag-WO 3 electrode for NO 2 sensor

2018 ◽  
Vol 5 (10) ◽  
pp. 171691 ◽  
Author(s):  
Rui Lu ◽  
Xiaoling Zhong ◽  
Shiguang Shang ◽  
Shan Wang ◽  
Manling Tang
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Different Temperatures ◽  
Size And Morphology

Pure WO 3 and Ag-WO 3 (mixed solid solutions Ag with WO 3 ) have been successfully synthesized by sol-gel method and the influences of calcination temperature on the particle size, morphology of the WO 3 and Ag-WO 3 nanoparticles were investigated. Powder X-ray diffraction results show that the hexagonal to monoclinic phase transition occurs at calcination temperature varying from 300°C to 500°C. SEM images show that calcination temperature plays an important role in controlling the particle size and morphology of the as-prepared WO 3 and Ag-WO 3 nanoparticles. The NO 2 gas sensing properties of the sensors based on WO 3 and Ag-WO 3 nanoparticles calcined at different temperatures were investigated and the experimental results exhibit that the gas sensing properties of the Ag-WO 3 sensors were superior to those of the pure WO 3 . Especially, the sensor based on Ag-WO 3 calcined at 500°C possessed larger response, better selectivity, faster response/recovery and better longer-term stability to NO 2 than the others at relatively low operating temperature (150°C).

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.

Gas sensing properties of Cu2O and its particle size and morphology-dependent gas-detection sensitivity

2014 ◽  
Vol 2 (33) ◽  
pp. 13641-13647 ◽  
Author(s):  
Xuejuan Wan ◽  
Jilei Wang ◽  
Lianfeng Zhu ◽  
Jiaoning Tang
Keyword(s):  
Particle Size ◽  
Gas Sensing ◽  
Detection Sensitivity ◽  
Gas Detection ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Key Factor ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Sensing Performance

Particle size and morphology-dependent gas-detection sensitivity were studied, and the results indicated that the particle stacking mode is a key factor influencing gas sensing performance.

Synthesis and Gas Sensing Properties of Palladium Doped Titanium Dioxide Nanoparticles

2013 ◽  
Vol 716 ◽  
pp. 74-77
Author(s):  
Fen Li ◽  
Qian Li ◽  
Xiao Pin Ma ◽  
Yan Yan Huang ◽  
Zhi Hong Jing
Keyword(s):  
Particle Size ◽  
Gas Sensing ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Optimum Concentration ◽  
Tetrabutyl Titanate ◽  
Palladium Chloride ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Doped Titanium Dioxide

Pd doped TiO2 nanoparticles were synthesized by sol-gel method with tetrabutyl titanate and palladium chloride as precursor materials. The products were characterized by XRD, SEM, FTIR and ICPOES technologies. The gas sensing properties of the products to 2-chloroethanol vapor were investigated. The results showed that the optimum concentration of Pd in the TiO2 nanoparticles was 3 mol% when the particle size of the anatase TiO2 nanoparticles was about 7 nm. Compared with pure TiO2 nanoparticles, the 3mol% Pd doped TiO2 nanoparticles exhibited higher gas sensing activities to 2-chloroethanol vapor.

Synthesis and Gas Sensing Properties of SnO2-CuO Nanocomposites

2013 ◽  
Vol 645 ◽  
pp. 129-132 ◽  
Author(s):  
Jantasom Khanidtha ◽  
Suttinart Noothongkaew ◽  
Supakorn Pukird
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Monoclinic Structure ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

SnO2-CuO nanocomposites have been synthesized with the simple co-precipitation method for gas sensing properties. Sn and CuO powder were the starting materials. The synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that SnO2-CuO nanocomposites have a tetragonal and monoclinic structure, respectively. SEM images verify that the some microballs are up to 10 µm and nanorods have a diameter range from 10-100 nm, while length ranges a few micrometers. The nanocomposite products were highly sensitivity to CO2gas at room temperature.

scholarly journals A comparative study on the electrical and gas sensing properties of thick films prepared with synthesized nano-sized and commercial micro-sized Fe2O3 powders

2017 ◽  
Vol 11 (4) ◽  
pp. 265-274 ◽  
Author(s):  
Ali Mirzaei ◽  
Maryam Bonyani ◽  
Shahab Torkian ◽  
Mahdi Feizpour ◽  
Anna Bonavita ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensing ◽  
Thick Films ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Sensing Applications ◽  
Transmission Electron ◽  
Gas Sensing Properties ◽  
Underlying Mechanisms

In this work, Fe2O3 nanoparticles (NPs) were successfully synthesized by Pechini sol-gel method. Scanning electron microscopy, transmission electron microscopy and X-ray diffraction characterizations were used to study the morphology and crystal structure of the synthesized products. The electrical and gas sensing behaviour of the synthesized and commercial Fe2O3 samples, prepared in the form of thick films, were studied. Though the commercial Fe2O3 powders had lower resistance but it was found that the synthesized Fe2O3 NPs had better gas sensing properties. The underlying mechanisms are discussed in details. The present findings show advantages of Fe2O3 NPs over micro-size particles for gas sensing applications.

Influence of Doping Methods on the Gas-Sensing Properties of CuO-SnO2 Sensors

2011 ◽  
Vol 306-307 ◽  
pp. 1289-1295
Author(s):  
Zhi Dong Lin ◽  
Wen Long Song ◽  
Han Min Yang ◽  
Ju Cheng Zheng
Keyword(s):  
Crystal Size ◽  
Gas Sensing ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Nano Crystalline ◽  
Gas Sensing Properties ◽  
Nitrogen Adsorption Isotherms ◽  
Higher Sensitivity

Nano crystalline SnO2was prepared by sol-gel with PEG surfactant. CuO was doped in the SnO2by mechanical mixture and reaction congelation from CuCl. The samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption isotherms (BET). The results indicated that the average crystal size of SnO2 at sintering temperature of 550 °C was 10 nm, the conglomeration size of SnO2was about 100 nm. The specific surface area of pure SnO2, mechanical doping SnO2and reaction doping SnO2were 110, 84, 72 m2/g, respectively. The thick film gas sensors made from these samples were examined. SnO2doped by different methods had different electrical and gas-sensing properties. The sensors based on CuO doped SnO2films exhibited less sensitive to ethanol gas but extremely higher sensitivity to H2S gas than that of pure SnO2.

Synthesis, Characterization and Gas Sensing Properties of Titanium Dioxide Nanoparticles by Sol-Gel Method

2016 ◽  
Vol 852 ◽  
pp. 238-243 ◽  
Author(s):  
Shi Guang Shang ◽  
Xin Li ◽  
Ling Zhao ◽  
Rui Lu ◽  
Hai Feng Chen
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Titanium Dioxide ◽  
Calcination Temperature ◽  
Gas Sensing ◽  
Sol Gel ◽  
Gel Method ◽  
Structure And Morphology ◽  
Gas Sensing Properties ◽  
Ph Level

Titanium dioxide (TiO2) nanoparticles were synthesized by sol-gel method and the influences of calcination temperature and pH level on the particle size, crystal structure and morphology of the TiO2 nanoparticles were investigated. X-ray diffraction patterns reveal that the anatase to rutile phase transition occurs at calcination temperature varying from 600°C to 800°C and the phase transformation temperature obviously decreases as the pH level of reaction solution decreases. Scanning electron microscopy images show that pH level and calcination temperature play an important role in controlling the particle size, crystal structure and morphology of the as-prepared TiO2 nanoparticles. The gas sensing properties of Ag-doped TiO2 nanoparticles were measured and the experimental results exhibit that the gas sensor based on Ag-doped TiO2 nanoparticle film has high sensitivity and fast response to ethanol.

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.

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