Tungsten trioxide-based thick-film NO sensor: design and investigation

Promotion effect of Pt on a SnO2–WO3 material for NO sensing

“…Several resistive-type materials have been evaluated for use in NO sensing, including semiconductors [8], organic polymers [9], ceramics [10], hybrid polymer/inorganic compounds [11], and composites [12][13][14][15]. Various sensing materials have been examined [3,[8][9][10][11][12][13][14][15], among which, tungsten trioxide is remarkable in semiconductor type gas sensor.…”

“…Various sensing materials have been examined [3,[8][9][10][11][12][13][14][15], among which, tungsten trioxide is remarkable in semiconductor type gas sensor. Tungsten trioxide is a wide-bandgap and n-type semiconductor, which in amorphous form (a-WO 3 ), seems to be the most promising material for deployment in film-based sensors because of its excellent sensitivity and selectivity [13].…”

“…Tungsten trioxide is a wide-bandgap and n-type semiconductor, which in amorphous form (a-WO 3 ), seems to be the most promising material for deployment in film-based sensors because of its excellent sensitivity and selectivity [13]. Some researchers used various methods to prepare different kinds of WO 3 and SnO 2 based as a gas sensor material for NO detection [8,[12][13][14]. Tomchenko et al prepared a WO 3 sensor by thin film coating method, sensor responses increase from 1.0 to 8.1 when the NO concentrations are increased from 10 to 300 ppm at 300°C [8].…”

“…Some researchers used various methods to prepare different kinds of WO 3 and SnO 2 based as a gas sensor material for NO detection [8,[12][13][14]. Tomchenko et al prepared a WO 3 sensor by thin film coating method, sensor responses increase from 1.0 to 8.1 when the NO concentrations are increased from 10 to 300 ppm at 300°C [8]. Chen and Tsang fabricate an Ag doped WO 3 sensor by impregnation way, and the sensor response is 38.3 when the NO concentration is 40 ppm at 250°C [13].…”

“…Hoa et al found a SnO x -SWNT composites sensor by rheotaxial growth thermal oxidation way, the responses increased from 0.1 to 23 when the NO concentrations were increased from 1 to 60 ppm [12]. However, the above WO 3 and SnO 2 sensing materials used in NO sensor require high working temperatures greater than 200°C [8,[12][13][14].…”