Improving the Selectivity of Metal Oxide Semiconductor Sensors for Mustard Gas Simulant 2-Chloroethyl Ethyl Sulfide by Combining the Laminated Structure and Temperature Dynamic Modulation.

Insufficient selectivity is a major constraint to the further development of metal oxide semiconductor (MOS) sensors for chemical warfare agents, and this paper proposed an improved scheme combining catalytic layer/gas-sensitive layer laminated structure with temperature dynamic modulation for the Mustard gas (HD) MOS sensor. Mustard gas simulant 2-Chloroethyl ethyl sulfide (2-CEES) was used as the target gas, (Pt + Pd + Rh)@AlO as the catalytic layer material, (Pt + Rh)@WO as the gas-sensitive layer material, the (Pt + Pd + Rh)@AlO/(Pt + Rh)@WO sensor was prepared, and the sensor was tested for 2-CEES and 12 battlefield environment simulation gases under temperature dynamic modulation. The results showed that the sensor only showed obvious characteristic peaks in the resistance response curves to HD under certain conditions (100-400 °C, the highest temperature was held for 1 s and the lowest temperature was held for 2 s), and its peak height reached 6.

High-Selectivity Laminated Gas Sensor Based on Characteristic Peak under Temperature Modulation.

Aiming at the bottleneck problem of insufficient selectivity of metal oxide gas sensors, a reliable scheme to improve selectivity is proposed, that is, a laminated sensor structure of a gas-sensitive membrane plus catalytic membrane combined with the temperature modulation technology. It is presented as a highly selective ethanol sensor as an example for verification. The laminated gas sensor is made of Sr@SnO as the gas-sensing membrane and ZSM-5 as the catalytic membrane by the microelectro mechanical system.

Cross-Interference of VOCs in SnO-Based NO Sensors.

In this work, we studied the influence of cross-interference effects between VOCs and NO on the performance of SnO and Pt-SnO-based gas sensors. Sensing films were fabricated by screen printing. The results show that the response of the SnO sensors to NO under air is higher than that of Pt-SnO, but the response to VOCs is lower than that of Pt-SnO.

TiO/(K,Na)NbO Nanocomposite for Boosting Humidity-Sensing Performances.

Nanomaterials of TiO, (KNa)NbO, and the TiO/(KNa)NbO nanocomposite were successfully synthesized by a hydrothermal method. Impedance-type humidity sensors were fabricated based on these materials. Our results reveal that the impedance of the TiO/(KNa)NbO sensor changes by 5 orders of magnitude with an ultrahigh sensing response of = 166 470 recorded at 100 Hz in the tested relative humidity (RH) range of 12-94%.