Rational Design of MoS2/C3N4 Hybrid Aerogel with Abundant Exposed Edges for Highly Sensitive NO2 Detection at Room Temperature

The quest for advanced gas sensing materials to detect toxic gases at low temperatures has recently received much attention to ensure indoor and outdoor air quality. For this purpose, two-dimensional transition-metal dichalcogenides (TMDs) have received widespread interest due to their highly active sites for the adsorption of gas molecules and outstanding electrical, chemical, and optical properties, which enable the materials to be used as supercapacitors, electrocatalysts, photocatalysts, battery materials, and sensors. In the present work, MoS2 was vertically grown on the surface of porous C3N4 nanosheets (NSs) to form MoS2/C3N4 hybrid aerogels via freeze drying. The gas sensing performance of the composites was investigated toward NO2 gas at room temperature (RT). The as prepared hybrid aerogel nanocomposite (MSN-2) showed abundant exposed active sites, a large number of pores, and high electronic density on the surface, thus exhibiting a 58-fold higher response than pristine MoS2 and C3N4 NSs. Furthermore, it showed short response/recovery time, commendable stability, and excellent selectivity toward NO2 gas. This work opens up an efficient way for the facile synthesis of edge-exposed MoS2 combined with highly porous C3N4 NSs for excellent NO2 gas sensing.