SnS2/MXene derived TiO2 hybrid for ultra-fast room temperature NO2 gas sensing

Nitrogen dioxide (NO2) is a prominent air pollutant that is harmful to both the environment and human health. Conventional NO2 sensors that are designed to operate at room temperature often come with severe performance compromises, especially in dynamic performance. This paper presents a new method for achieving ultra-fast NO2 gas sensing and recovery dynamics using a nanohybrid of SnS2 and MXene derived TiO2. With its unique 2D structure, MXene derived TiO2 provides a unique platform on which SnS2 can be decorated, forming heterojunctions as well as significantly enlarged surface area, both contributing to enhanced gas sensing properties. At room temperature operation, the fabricated nanohybrid based sensor exhibits a large response of 115 toward 1000 ppm NO2 gas and an ultra-fast recovery of 10 s. This level of dynamic performance is unprecedented, rendering fast room temperature gas sensing a practical reality.