NiO/Ti3C2Tx MXene nanocomposites sensor for ammonia gas detection at room temperature

Poultry feeding will lead to a large amount of ammonia(NH3) emissions, which will seriously affect the quality of meat. Herein, we report a resistive sensor based on NiO/Ti3C2Tx sensitive nanocomposites for NH3 detection in a natural environment. The nanocomposites were prepared by modifying two-dimensional（2D） Ti3C2Tx MXene with nickel oxide (NiO) nanoparticles (NPs) by a simple ultrasonic self-assembly method. The results show that the NiO/Ti3C2Tx MXene nanocomposite sensor exhibits a high sensitivity of 6.13 % to 50 ppm NH3 at room temperature (RT), which is 8.7 times higher than that of the pure Ti3C2Tx MXene sensor. In other words, the addition of NiO NPs can significantly enhance the gas-sensing response of pure Ti3C2Tx MXene to NH3 at RT. Meanwhile, the response and recovery time were also effectively improved (63 s/19 s) due to the addition of NiO NPs. Furthermore, the response of the nanocomposite sensor to volatile organic compounds (VOCs) was investigated, and the results showed its prospective and high selectivity. On the other hand, the nanocomposite sensor exhibits good repeatability and long-term stability. Finally, a possible sensing mechanism is proposed to improve sensor performance.