Highly sensitive sensors based on quasi-2D rGO/SnS2 hybrid for rapid detection of NO2 gas

Abstract Nitrogen dioxide (NO 2 ) sensing is important in terms of the agriculture development and healthcare monitoring. However, relatively poor recovery kinetics at a low temperature is still a problem for NO 2 sensing and remains to be solved. In this work, we combine the excellent sensing properties and gas adsorption capacity of two- dimensional (2D) tin disulfide (SnS 2 ) hexagonal nanoflakes with the beneficial electrical properties of graphene to build high-performance NO 2 sensors by a simple and low-cost method. We found that the sensors based on the quasi-2D rGO-SnS 2 hybrids exhibited exclusive selectivity towards NO 2 . The presence of rGO in hybrids decreased optimal working temperature effectively. Sensors based on 0.8% rGO-SnS 2 (G-SS) show almost an order of magnitude increase in response (32) compared to pristine SnS 2 (3.5). Especially, the response/recovery time is 50/48 s, respectively, demonstrating the favorable response/recovery kinetics of sensors. Such significant features can be attributed to the synergistic effect of the quasi-2D G-SS hybrid and the local heterojunctions in the interface between SnS 2 and rGO.