Abstract
In recent years, two-dimensional layered material MXene has attracted extensive attention in the fields of sensors due to its large specific surface area and rich active sites. So, we employed multilayer Ti3C2TX and SnO2 microspheres to prepare SnO2/MXene composites for enhancing gas-sensing properties of pristine SnO2. The composite was brushed on a microelectromechanical system (MEMS) platform to make resistance-type gas sensors with low power consumption. The gas-sensing results show that the SnO2/MXene sensor with the best composite ratio (SnO2: MXene mass ratio is 5:1, named SM-5) greatly improves gas sensitivity of SnO2 sensor, among which the sensitivity to ethanol gas is the highest. At the same time, the composite also speeds up the response recovery speed of the sensor. When the SM-5 sensor worked at its optimal temperature 230 °C, its response value to 10 ppm ethanol reaches 5.0, which is twice that of the pristine SnO2 sensor. Its response and recovery time are only 14 s and 26 s, respectively. The sensing mechanism of the composite is discussed according to the classical the space charge or depletion layer model. It is concluded that the Schottky barrier of composites and the metal properties of Ti3C2Tx are responsible for improvement of the gas-sensing properties of the composite.
Highlights
Volatile organic compounds (VOCs) pollute the environment, and cause acute and chronic effects on human health through respiratory and skin pollution
microelectromechanical system (MEMS) gas is prepared by adiffraction drop-coating through mixing sensing whichThe canMEMS
SnO2/MXene composites were fabricated through a facile hydrothermal method
Summary
Volatile organic compounds (VOCs) pollute the environment, and cause acute and chronic effects on human health through respiratory and skin pollution. Many methods can be used to improve the performance of SnO2 gas sensors, such as mechanical mixing of mesoporous materials with high specific surface area, precious metals composite, preparation of nanomaterials with heterojunctions, etc. Li et al, modified the sensitivity and selectivity of SnO2 gas sensor by mechanically mixing a novel high surface area mesoporous material [20], and Wang et al, prepared Au-SnO2 composite nanoparticles to increase the sensitivity of the hydrogen sensor [21]. The gas-sensing test results show that the SnO2 /MXene sensor with the best composite ratio greatly improves the sensitivity of the SnO2 sensor to gases (ammonia, nitrogen dioxide, hydrogen sulfide, paraxylene, toluene, benzene, methanal, acetone and ethanol), among them the sensitivity to ethanol gas is the highest. It is concluded that the Schottky barrier of composites and the metal properties of Ti3 C2 Tx are responsible for the improvement of the gas-sensing properties of the composite
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
