Selective detection of HCHO gas using mixed oxides of ZnO/ZnSnO3

Improving humidity selectivity in formaldehyde gas sensing by a two-sensor array made of Ga-doped ZnO

“…However, the recovery time prolonged after higher concentration formaldehyde was switched off, which would be studied further.The different chemical mechanisms of MOS sensors to formaldehyde and to water might be the base for the sensor array. Ion-sorbed oxygen behaves as the electron extractor from the bulk semiconductors, and formaldehyde is commonly postulated to be oxidized by that ion-sorbed oxygen, as shown in the following reactions [11,14,23]:…”

Silicon-based micro-gas sensors for detecting formaldehyde

“…Semiconductor gas sensors have been widely used for indoor gas detection [15,16]. Many researchers reported on semiconductor formaldehyde gas sensors with different structures, such as ceramic plate structure [17,18], ceramic tube structure [19][20][21][22] and micro-hotplate structure [23,24]. In particular, it is desirable for gas sensors to be fabricated on silicon substrate so as to integrate them with their control circuits [23][24][25][26].…”

Porous cobalt oxide nanowires: Notable improved gas sensing performances

“…We can see that the sensor response increases at an initial stage but decreases afterwards with the continuing rise of temperature, thereby passing through a zenith at 350°C. This can be explained qualitatively from a dynamic balance between initial fast adsorption of ethanol molecule and the further acceleration of desorption, as the temperature maintains rising [18]. Moreover, this can also be understood by considering the other possibility: the reaction rate between the ethanol and the sensing material increases as temperatures increases to the optimal value, and further decrease of sensor response after the optimum can be ascribed to the reduced gas concentration due to the combustion of the tested gas [19].…”