Enhanced ammonia sensing performance based on MXene-TiCT multilayer nanoflakes functionalized by tungsten trioxide nanoparticles.

Low-power consumption and high sensitivity are highly desirable for a vast range of NH sensing applications. As a new type of two-dimension (2D) material, TiCT is extensively studied for room temperature NH sensors recently. However, the TiCT MXene based gas sensors suffer mainly from low sensitivity. Herein, we report a sensitive TiCT/WO composite resistive sensor for NH detection. The TiCT/WO composite consisting of WO nanoparticles anchored on TiCT nanoflakes were synthesized successfully with a facile ultra-sonication technique. The composite sensor with optimized components exhibits a high sensitivity of 22.3% for 1 ppm NH at room temperature, which is 15.4 times higher than the pure TiCT sensor. Furthermore, the composite sensor has excellent reproducibility, good long-term stability, and high selectivity to NH. The relative humidity influence on NH gas sensing properties of the sensors was systematically studied. This research provides an efficient route for the preparation of novel MXene-based sensitive materials for high-performance NH sensors.