Flexible resistive NO2 gas sensor of SnO2@Ti3C2Tx MXene for room temperature application

SnO 2 nanoparticles@Ti 3 C 2 T x MXene have been successfully synthesized by a flexible solvothermal method. The Ti 3 C 2 T x MXene was evenly anchored by the SnO 2 nanoparticles (∼5 nm) through the controllable assembly heterojunction . Ti 3 C 2 T x MXene contributed to the improvement of material conductivity compared to SnO 2 nanoparticles. The combination of SnO 2 @Ti 3 C 2 T x exhibits excellent sensitivity and selectivity to NO 2 at room temperature (RT). Compared with pure Ti 3 C 2 T x MXene, the sensitivity of TCS1.5 nanocomposite increases more than 20 times to 300 ppm NO 2 at RT. In order to explore the sensing mechanism of SnO 2 @Ti 3 C 2 T x nanocomposite to NO 2 , nitrogen adsorption-desorption isotherm technology and DFT calculations were performed. They demonstrated that the high specific surface area, well-proportioned heterogeneous structure of SnO 2 @Ti 3 C 2 T x MXene, and the vital ionic bonds of Sn–N and O–N formed between substrate and NO 2 gas had beneficial effect on improving the gas response capability.