Two-dimensional Ti3C2Tx MXene/SnO nanocomposites: Towards enhanced response and selective ammonia vapor sensor at room temperature

Ammonia detection is significant for human health in our daily life. Ammonia exhaled from people plays a role in diagnosing diseases, and ammonia from ambient air can harm our bodies. In this work, Ti3C2Tx MXene/SnO is synthesized by the one-step hydrothermal method. From the XRD, SEM, TEM, XPS analysis results, it is concluded that Ti3C2Tx MXene/SnO is successfully prepared. Moreover, a special bonding formed between SnO and Ti3C2Tx MXene inhibits the oxidation of SnO. At room temperature (23 ± 2 °C) of operating temperature, this Ti3C2Tx MXene/SnO sensor exhibits high sensing performances of 7.8 for 200 ppm ammonia vapor and good selectivity, repeatability, moisture resistance, and long-term stability. Moreover, it shows a relatively short response time and recovery time of 61 s and 119 s. Due to the different work functions of Ti3C2Tx MXene and SnO, a Schottky barrier is formed between the SnO nanosheets and the Ti3C2Tx multi-layers. The p-n junction enriches the electron on the surface of Ti3C2Tx MXene/SnO that enhancing the response. It’s hoped this material with such excellent selectivity and low ammonia detection will help diagnose kidney diseases in the future. The gas sensor fabricated by two-dimensional Ti3C2Tx MXene/SnO nanocomposites exhibits high response, good selectivity, repeatability, moisture resistance, and long-term stability towards NH3 under the operating temperature of room temperature, making it to be a promising candidate for practical detectors for NH3 of diagnosed kidney diseases. [Display omitted] •2D Ti3C2Tx MXene/SnO was successfully obtained via one-step hydrothermal method.•2D Ti3C2Tx MXene/SnO displays high response to low-concentration ammonia.•2D Ti3C2Tx MXene/SnO exhibits good dynamic properties, selectivity, and repeatability.•2D Ti3C2Tx MXene/SnO can be expected for development of an excellent ammonia gas sensor.