Hydrogen sensing characteristics of WO3 thin film conductometric sensors activated by Pt and Au catalysts

Ippolito, Samuel J.; Kandasamy, Sasikaran; Kalantar‐zadeh, Kourosh; Włodarski, W.

doi:10.1016/j.snb.2004.11.092

Cited by 185 publications

(83 citation statements)

References 14 publications

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“…In metal oxide sensors, the electrical resistance of the film changes when exposed to a target gas. Also, among metal oxides, WO 3 is widely used to detect many gases like H 2 , H 2 S, NO 2 and VOC [20][21][22][23]. Moreover, it has been shown that the addition of an appropriate amount of noble metal additives promotes chemical reactions by reducing activation energy between the surface of metal oxide and target gas.…”

Section: Open Accessmentioning

confidence: 99%

Fabrication of Pd Doped WO3 Nanofiber as Hydrogen Sensor

2013

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Pd doped WO 3 fibers were synthesized by electro-spinning. The sol gel method was employed to prepare peroxopolytungstic acid (P-PTA). Palladium chloride and Polyvinyl pyrrolidone (PVP) was dissolved in the sol Pd:WO 3 = 10% molar ratio. The prepared sol was loaded into a syringe connected to a high voltage of 18.3 kV and electrospun fibers were collected on the alumina substrates. Scanning electron microscope (SEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were used to analyze the crystal structure and chemical composition of the fibers after heat treatment at 500 °C. Resistance-sensing measurements exhibited a sensitivity of about 30 at 500 ppm hydrogen in air, and the response and recovery times were about 20 and 30 s, respectively, at 300 °C. Hydrogen gas sensing mechanism of the sensor was also studied.

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Section: Open Accessmentioning

confidence: 99%

Fabrication of Pd Doped WO3 Nanofiber as Hydrogen Sensor

2013

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“…In principle, MOS sensors would utilize changes in the resistance of a sensing layer to detect the presence of a gas. The most frequently investigated oxide semiconductors for gas sensing applications include SnO 2 [2][3][4], ZnO [5,6], WO 3 [7][8][9], and TiO 2 [10][11][12]. In the present work, we utilize the extraordinary hydrogen-induced metallization [13] that occurs in ZnO to produce a high-performance H 2 sensor with high selectivity.…”

Section: Introductionmentioning

confidence: 99%

Highly sensitive and selective H2 sensing by ZnO nanofibers and the underlying sensing mechanism

Katoch

Choi

Kim

et al. 2015

Journal of Hazardous Materials

107

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“…We have considered a literary review of works and publications on the gas-sensitive characteristics of various sensor structures in gas mixtures of air with hydrogen [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The interest of authors of the works has been concentrated on the search of catalytic additives to tin dioxide and search of new semiconductive metal oxides.…”

Section: Introductionmentioning

confidence: 99%

Investigation of gas-sensitivity of sensor structures to hydrogen in a wide range of temperature, concentration and humidity of gas medium

Малышев

Pislyakov

2008

Sensors and Actuators B: Chemical

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Investigation of gas-sensitivity of sensor structures to hydrogen in a wide range of temperature, concentration and humidity of gas medium a b s t r a c t Response to H 2 of seven sensor structures of SnO 2 with various catalytic additives, made by thick-film technology, was investigated in a dry gas medium at a concentration of 200 ppm H 2 in a temperature range of 100-600 • C. Concentration dependence of six sensors (pure SnO 2 and doped with five catalytic additives: 3% Pd, 3% La 2 O 3 , 1% Pt + 3% Pd, 1% Sb 2 O 5 + 3% La 2 O 3 and 3% Pd with a support layer from Al 2 O 3 ) was investigated in a range of 1-19,700 ppm H 2 of different relative humidity (RH) in a range of 0-100% RH at two operating temperatures. The resistance and response of the sensors weakly depended on the humidity of the gas medium at RH ≥ 0 or 10%. Arithmetic mean values of response and resistance in the range of 0 (10)-100% RH were approximated by linear functions of log(S ma − 1) = B + n log C and log R ma = A + k log C, respectively.Based on the comparative analysis of experimental data (response to H 2 , reproducibility of indications, influence of humidity on the resistance and response, response threshold and a resistance drift in pure air), the best for H 2 detection were the two sensor structures of pure SnO 2 and SnO 2 + 3% La 2 O 3 , working at temperatures 500 • C and 450 • C, respectively. Formulas for resistance and response of these sensors were presented, which allowed estimation of H 2 concentration in air based on the measured parameters. Reproducibility of indications in the range of 1-19,700 ppm H 2 was within 4-10%. The response threshold was 0.08 ± 0.006 ppm H 2 in the mentioned range of humidity at the response equal to 1.1.The interpretation was given for the mechanism of interaction of H 2 with the catalytic surface of semiconductive sensors. The present sensors can be recommended as the primary transducer of H 2 concentration in air for the gas control devices.

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Hydrogen sensing characteristics of WO3 thin film conductometric sensors activated by Pt and Au catalysts

Cited by 185 publications

References 14 publications

Fabrication of Pd Doped WO3 Nanofiber as Hydrogen Sensor

Fabrication of Pd Doped WO3 Nanofiber as Hydrogen Sensor

Highly sensitive and selective H2 sensing by ZnO nanofibers and the underlying sensing mechanism

Investigation of gas-sensitivity of sensor structures to hydrogen in a wide range of temperature, concentration and humidity of gas medium

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