Enhanced ammonia sensing response based on Pt-decorated Ti 3 C 2 T x /TiO 2 composite at room temperature

• Published in: Nanotechnology 2023-05, Vol.34 (20), p.205501
• Main Authors: Zhang, Haifeng, Wang, Li, Zou, Yecheng, Li, Yongzhe, Xuan, Jingyue, Wang, Xiaomei, Jia, Fuchao, Yin, Guangchao, Sun, Meiling
• Format: Article
• Language: English
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/1361-6528/acbbd2

Herein, we report a Pt-decorated Ti C T /TiO gas sensor for the enhanced NH sensing response at room temperature. Firstly, the TiO nanosheets (NSs) are grown onto the two-dimensional (2D) Ti C T by hydrothermal treatment. Similar to Ti C T sensor, the Ti C T /TiO sensor has a positive resistance variation upon exposure to NH , but with slight enhancement in response. However, after the loading of Pt nanoparticles (NPs), the Pt-Ti C T /TiO sensor shows a negative response with significantly improved NH sensing 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-Ti C T /TiO gas sensor to 100 ppm NH is about 45.5%, which is 13.8- and 10.8- times higher than those of Ti C T and Ti C T /TiO gas sensors, respectively. The experimental detection limit of the Pt-Ti C T /TiO gas sensor to detect NH is 10 ppm, and the corresponding response is 10.0%. In addition, the Pt-Ti C T /TiO gas sensor shows the fast response/recovery speed (23/34 s to 100 ppm NH ), 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.