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 Ti3C2Tx MXene sensing material by a chemical etchant for ammonia sensing, which shows high response and excellent selectivity to ammonia (NH3) at room temperature of operating temperature. A key point of this work is the thermal treatment temperature of the sensing ceramic tube at 280 degrees C, which removes the adsorbed water and partially oxidized the material. In ambient condition, Ti3C2Tx MXene-280 shows the response to 500 ppm NH3 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 Ti3C2Tx MXene-280 sensor to NH3 at room temperature are ascribed to the powerful hydrogen bond formed between the OH-, O-2(-) functional groups on Ti3C2Tx MXene-280 and NH3, as well as the synergistic effect of TiO2 and Ti3C2Tx MXene, generated after heating treatment, which increases the electron transport efficiency. The results demonstrated that the facilely designed Ti3C2Tx MXene-280 sensor is believed to contribute to developing future portable and selective sensing electronics at room temperature.

Automated summary

This paper develops a two-dimensional material, Ti3C2Tx MXene sensor, with high response and excellent selectivity to ammonia at room temperature, achieved through thermal treatment to improve electron transport efficiency. With good moisture resistance, the sensor has the potential to contribute to the development of future portable and selective sensing electronics at room temperature.