Partially oxidized Ti3C2Tx MXene-sensitive material-based ammonia gas sensor with high-sensing performances for room temperature application

It is highly desirable to develop sensors with high response and selectivity at room temperature of operating temperature. Besides, efficient and low-cost sensors are also required for future social development. In this paper, it is developed a detector with two-dimensional (2D) material of Ti 3 C 2 T x MXene sensing material by a chemical etchant for ammonia sensing, which shows high response and excellent selectivity to ammonia (NH 3 ) at room temperature of operating temperature. A key point of this work is the thermal treatment temperature of the sensing ceramic tube at 280 °C, which removes the adsorbed water and partially oxidized the material. In ambient condition, Ti 3 C 2 T x MXene-280 shows the response to 500 ppm NH 3 with 147 %, and the counterpart response and recovery time are 67 and 157 s at room temperature of operating temperature, respectively. In the environment of different relative humidity, its sensing performance is maintained at around 50 % of the initial performance, which shows great moisture resistance. The higher response and good selectivity of Ti 3 C 2 T x MXene-280 sensor to NH 3 at room temperature are ascribed to the powerful hydrogen bond formed between the OH − , O 2 − functional groups on Ti 3 C 2 T x MXene-280 and NH 3 , as well as the synergistic effect of TiO 2 and Ti 3 C 2 T x MXene, generated after heating treatment, which increases the electron transport efficiency. The results demonstrated that the facilely designed Ti 3 C 2 T x MXene-280 sensor is believed to contribute to developing future portable and selective sensing electronics at room temperature.