Three-Dimensional MoS 2 /Reduced Graphene Oxide Nanosheets/Graphene Quantum Dots Hybrids for High-Performance Room-Temperature NO 2 Gas Sensors

This study presents three-dimensional (3D) MoS /reduced graphene oxide (rGO)/graphene quantum dots (GQDs) hybrids with improved gas sensing performance for NO sensors. GQDs were introduced to prevent the agglomeration of nanosheets during mixing of rGO and MoS . The resultant MoS /rGO/GQDs hybrids exhibit a well-defined 3D nanostructure, with a firm connection among components. The prepared MoS /rGO/GQDs-based sensor exhibits a response of 23.2% toward 50 ppm NO at room temperature. Furthermore, when exposed to NO gas with a concentration as low as 5 ppm, the prepared sensor retains a response of 15.2%. Compared with the MoS /rGO nanocomposites, the addition of GQDs improves the sensitivity to 21.1% and 23.2% when the sensor is exposed to 30 and 50 ppm NO gas, respectively. Additionally, the MoS /rGO/GQDs-based sensor exhibits outstanding repeatability and gas selectivity. When exposed to certain typical interference gases, the MoS /rGO/GQDs-based sensor has over 10 times higher sensitivity toward NO than the other gases. This study indicates that MoS /rGO/GQDs hybrids are potential candidates for the development of NO sensors with excellent gas sensitivity.