Enhanced ammonia sensing response based on Pt-decorated Ti3C2Tx/TiO2composite at room temperature

Herein, we report a Pt-decorated Ti₃C₂T_x/TiO₂gas sensor for the enhanced NH₃sensing response at room temperature. Firstly, the TiO₂nanosheets (NSs) arein situgrown onto the two-dimensional (2D) Ti₃C₂T_xby hydrothermal treatment. Similar to Ti₃C₂T_xsensor, the Ti₃C₂T_x/TiO₂sensor has a positive resistance variation upon exposure to NH₃, but with slight enhancement in response. However, after the loading of Pt nanoparticles (NPs), the Pt-Ti₃C₂T_x/TiO₂sensor shows a negative response with significantly improved NH₃sensing performance. The shift in response direction indicates that the dominant sensing mechanism has changed under the sensitization effect of Pt NPs. At room temperature, the response of Pt-Ti₃C₂T_x/TiO₂gas sensor to 100 ppm NH₃is about 45.5%, which is 13.8- and 10.8- times higher than those of Ti₃C₂T_xand Ti₃C₂T_x/TiO₂gas sensors, respectively. The experimental detection limit of the Pt-Ti₃C₂T_x/TiO₂gas sensor to detect NH₃is 10 ppm, and the corresponding response is 10.0%. In addition, the Pt-Ti₃C₂T_x/TiO₂gas sensor shows the fast response/recovery speed (23/34 s to 100 ppm NH₃), high selectivity and good stability. Considering both the response value and the response direction, the corresponding gas-sensing mechanism is also deeply discussed. This work is expected to shed a new light on the development of noble metals decorated MXene-metal oxide gas sensors.

Exploring the catalytic activity of Nb4C3Tx MXene towards the degradation of nitro compounds and organic dyes by in situ decoration of palladium nanoparticles

We report on the catalytic activity of Nb4C3Tx based composites towards the catalytic reduction of nitro compounds and organic dyes for the first time.