Facile solvothermal synthesis of ZnO/Ti3C2Tx MXene nanocomposites for NO2 detection at low working temperature

Nitrogen dioxide sensors with high performance have been expected for practical applications in environmental monitoring. Herein, we demonstrate a NO2 gas sensor with enhanced performance based on ZnO/Ti3C2Tx nanocomposites. The hawthorn shaped ZnO spheres/Ti3C2Tx nanocomposites with regular morphology are successfully synthesized via a facile solvothermal method. The NO2 sensing properties are greatly improved by introducing the Ti3C2Tx sheets which significantly reduce the operating temperature and improve the gas sensitivity. The response to 8 ppm NO2 improves to 3.4, and the response and recovery characteristic substantially speeds up to 191 s and 254 s at lower working temperature. The excellent NO2 sensing properties of ZnO/Ti3C2Tx nanocomposites are attributed to the high surface area, the modulation of carrier density, the formation of ZnO/Ti3C2Tx heterojunction. Such excellent performance showed the promising application of hawthorn shaped ZnO spheres/Ti3C2Tx nanocomposites for NO2 gas sensing.