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.