Time‐Frequency Domain NO <sub>2</sub> ‐Humidity Sensor with Full‐Range Tolerance Based on Pt Single‐Atom Sensitized Nb <sub>2</sub> CT <i> <sub>x</sub> </i> Nanosheets
Zitong Kan, Wenbo Hu, Chencheng Hu, Fangyu Shi, Long Yang, Qingqing Zhou, Wei Zhang, Qi Yu, Biao Dong, Hongwei Song, Lin Xu
Abstract
Abstract Real‐time in situ detection of NO 2 is crucial for ensuring industrial safety and healthcare. However, conventional gas sensors face challenges from environmental humidity interference, limiting their reliability in practical applications. This study presents a dual‐mode, full‐range NO 2 ‐humidity sensing platform based on Pt single‐atom‐sensitized Nb 2 CT x nanosheets (Pt SA‐Nb 2 CT x ) integrated with TPU fiber mats (Pt SA‐Nb 2 CT x @TPU). Combining resistive gas sensing and capacitive humidity sensing within a single device, this platform enables simultaneous NO 2 and humidity detection with full‐range humidity tolerance. The uniformly dispersed Pt single‐atoms on the Nb 2 CT x nanosheets catalyze oxygen molecule dissociation and provide additional surface‐active adsorption sites, achieving a 9.1‐fold improvement in resistance response to 5 ppm NO 2 and a 25.7‐fold increase in capacitance response at 95% relative humidity. Importantly, the unaffected capacitive response allows precise calibration of NO 2 concentration using resistance and capacitance, ensuring accurate NO 2 detection across diverse and fluctuating humidity. Leveraging time‐ and frequency‐domain NO 2 ‐humidity sensing capability, the Pt SA‐Nb 2 CT x @TPU sensor is successfully integrated into self‐designed functional modules to realize humidity tracking, industrial NO 2 concentration alarming in full‐humidity range as well as asthma prevention and alarm applications. This study offers a novel solution for humidity‐compensated NO 2 detection, advancing the applicability of gas sensors in complex and dynamic environments.