Development of Highly Sensitive and Humidity Independent Room Temeprature NO2 Gas Sensor Using Two Dimensional Ti3C2Tx Nanosheets and One Dimensional WO3 Nanorods Nanocomposite

Room temperature gas sensors have been widely explored in gas sensor technology for real-time applications. However, humidity has found to affect the room temperature sensing and the sensor life, necessitating the development of novel sensing materials with high sensitivity and stability under humid conditions at room temperature. In this work, the room temperature sensing performance of a Ti3C2Tx decorated, WO3 nanorods based nanocomposite has been investigated. The hydrothermally synthesized WO3/Ti3C2Tx nanocomposite has been investigated for structural, morphological, and electrical studies using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and Brunanuer-Emmett-Teller techniques. The WO3/Ti3C2Tx sensors have been found to be highly selective to NO2 at room temperature and exhibit much higher sensitivity in comparison to pristine WO3 nanorods. Furthermore, sodium l-ascorbate treated Ti3C2Tx sheets in WO3/Ti3C2Tx enhanced the stability and reversibility of the sensor toward NO2 even under variable humidity conditions (0-99% relative humidity). This study shows the potential room temperature sensing application of a WO3/Ti3C2Tx nanocomposite-based sensor for detecting NO2 at sub-ppb level. Further, a plausible sensing mechanism based on WO3/Ti3C2Tx nanocomposite has been proposed to explain the improved sensing characteristics.