Highly Selective No2 Gas Sensing with Sno2-Ti3c2tx Nanocomposites Synthesized Via the Microwave Process

Abstract

MXene materials are becoming increasingly prevalent in gas sensing for their metallic conductivity and the functional groups on their surfaces. In this study, we prepared a SnO 2 - (0.5, 1, 2, and 5 wt%) Ti 3 C 2 T x MXene nanocomposite for NO 2 gas sensing. A sensor with 2 wt% Ti 3 C 2 T x showed improved gas responses and was subsequently irradiated by microwaves (MWs) for 1, 3, 5, and 8 min. Gas-sensing studies demonstrated that at 150 °C, a MW-irradiated SnO 2 -(2 wt%) Ti 3 C 2 T x nanocomposites exhibited a response of 24.8 to 10 ppm NO 2 , being superior to those of pristine Ti 3 C 2 T x , pristine SnO 2 and un-irradiated SnO 2 -(2 wt%) Ti 3 C 2 T x nanocomposite gas sensors. In addition, the optimized gas sensor exhibited high stability and excellent NO 2 selectivity. The sensing mechanism is explained by the synergetic effects of SnO 2 and Ti 3 C 2 T x and the presence of functional groups on Ti 3 C 2 T x .

Keywords: NO2 gas sensor, SnO2, Ti3C2Tx, Nanocomposite, microwave irradiation