Fabrication and formaldehyde gas-sensing property of ZnO–MnO2 coplanar gas sensor arrays

A ppb-Level Formaldehyde Gas Sensor Based on Rose-Like Nickel Oxide Nanoparticles Prepared Using Electrodeposition Process

“…Hence, the responses are enhanced with the increasing temperature. 39 But the reduction in response above 230 C is due to the fact that the adsorption reaction is proverbially exothermic. At higher temperature, the basic reaction ((1/2)O 2ðgÞ þe À !O À ads Þ will proceed to left, which leads to the decrease of the trapped electrons from the conductance band.…”

2-Methyl-2,4-pentanediol gas sensor properties of nano-SnO2 flat-type coplanar gas sensing arrays at low detection limit

“…All the gas sensing properties were studied in a static testing instrument which was developed by our laboratory [27]. The basic measuring circuit of the static testing instrument is similar to the one presented in literature [28,29].…”

“…For n-type SnO 2 , the thickness of the surface electron depletion layer will be narrower at lower temperature. So, the change of resistance will be smaller when the gas sensors are exposed to reducing gas [27]. Besides, the elevated operating temperature provides the high activation energy to promote the transition from physisorption to chemisorption and the chemical reaction between MPD molecules and the oxygen [32][33][34].…”

“…Therefore, the response increases with the rise in operating temperature. While the basic adsorption reaction ( [27,28], the reaction may change when the temperature continues to rise. It means that with rising the operating temperature, the trapped electrons will come back to the conduction band and the thickness of depletion layer will be narrower, which will result in a lower response.…”

Gas-sensing properties and in-situ diffuse-reflectance Fourier-transform infrared spectroscopy study of diethyl ether adsorption and reactions on SnO2 film

“…However, these methods are associated with various disadvantages, being either expensive, or time-consuming, requiring complex experimental apparatus or large instrument volume, or involving toxic solvents or reagents [8][9][10][11][12]. On the other hand, gas sensors based on metal oxide semiconductors, like SnO 2 , ZnO and Fe 2 O 3 have attracted much attention due to their unique features, such as low cost, high sensitivity, fast response, relative simplicity and portability [13][14][15].…”