High Sensitivity Bi₂O₃/Ti₃C₂T_x Ammonia Sensor Based on Improved Synthetic MXene Method at Room Temperature

The MXene Ti₃C₂T_x was synthesized using hydrofluoric acid and an improved multilayer method in this study. Subsequently, a Bi₂O₃/Ti₃C2T_x composite material was produced through hydrothermal synthesis. This composite boasts a unique layered structure, offering a large surface area that provides numerous contact and reaction sites, facilitating the adsorption of ammonia on its surface. The prepared Bi₂O₃/Ti₃C₂T_x-based sensor exhibits excellent sensing performance for ammonia gas, including high responsiveness, good repeatability, and rapid response-recovery time. The sensor's response to 100 ppm ammonia gas is 61%, which is 11.3 times and 1.6 times the response values of the Ti₃C₂T_x gas sensor and Bi₂O₃ gas sensor, with response/recovery times of 61 s/164 s at room temperature, respectively. Additionally, the gas sensitivity mechanism of the Bi₂O₃/Ti₃C₂T_x-based sensor was analyzed, and the gas sensing response mechanism was proposed. This study shows that the sensor can effectively enhance the accuracy and precision of ammonia detection at room temperature and has a wide range of application scenarios.