Enhanced ammonia sensing performance based on MXene-Ti₃C₂T_x multilayer nanoflakes functionalized by tungsten trioxide...

Low-power consumption and high sensitivity are highly desirable for a vast range of NH₃ sensing applications. As a new type of two-dimension (2D) material, Ti₃C₂T_x is extensively studied for room temperature NH₃ sensors recently. However, the Ti₃C₂T_x MXene based gas sensors suffer mainly from low sensitivity. Herein, we report a sensitive Ti₃C₂T_x/WO₃ composite resistive sensor for NH₃ detection. The Ti₃C₂T_x/WO₃ composite consisting of WO₃ nanoparticles anchored on Ti₃C₂T_x 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 NH₃ at room temperature, which is 15.4 times higher than the pure Ti₃C₂T_x sensor. Furthermore, the composite sensor has excellent reproducibility, good long-term stability, and high selectivity to NH₃. The relative humidity influence on NH₃ 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 NH₃ sensors.