Construction of MoS2/SnO2 heterostructures for sensitive NO2 detection at room temperature

Molybdenum disulfide (MoS2) has sparked immense interests as a novel gas sensing material due to its inherent layered structure and large surface-to-volume ratio. However, the obstacles of insufficient sensitivity and poor recoverability for MoS2-based gas sensors need to be resolved for the further applications. Herein, we report the construction of MoS2 nanosheets based p–n heterostructures for the purposes of achieving excellent NO2 detection at room temperature. After functionalized with tin oxide (SnO2) nanoparticles, the optimal MoS2/SnO2 heterostructure-based gas sensor exhibits a response of 18.7 to 5 ppm nitrogen dioxide (NO2), an outstanding selectivity compared with other gases, and an excellent long-term stability for 4 weeks. The enhanced sensing performance of MoS2/SnO2 heterostructures can be ascribed to the unique 2D/0D nanostructures and the formation of numerous p–n heterojunctions. Therefore, construction of p–n heterostructures provides a versatile solution to overcome the sensing issues of MoS2-based gas sensors and also paves a new way for others room temperature sensor applications.