Rational synthesis of molybdenum disulfide nanoparticles decorated reduced graphene oxide hybrids and their application for high-performance NO2 sensing

In this work, we have reported a novel NO 2 sensor using molybdenum disulfide nanoparticles (MoS 2 NPs) decorated RGO (MoS 2 -RGO) hybrids as sensing materials, where MoS 2 -RGO hybrids were prepared by a two-step wet-chemical method. Firstly, MoS 2 NPs prepared by modified liquid exfoliation method from bulky MoS 2 powder. Then, MoS 2 -RGO hybrids were obtained by self-assembly of MoS 2 NPs and GO nanosheets, followed by a facile hydrothermal treatment progress. The combined characterizations indicate that MoS 2 NPs with the size of 3–5 nm are uniformly dispersed on RGO nanosheets. Most importantly, the sensor based on MoS 2 -RGO hybrids could detect NO 2 at room temperature. To further improve sensing performances, especially response and recovery rate, sensing properties are further examined by increasing the operation temperature to 160 °C. It is notably seen that MoS 2 -RGO-based NO 2 sensor not only shows improved sensitivity to NO 2 compared to pure RGO-based sensor, but also exhibits fast response and recovery characteristics (response time and recovery time are 8 s and 20 s toward 3 ppm NO 2 ). This work paves a new way for application of MoS 2 and RGO in chemical sensors, providing an effective method for fabrication of NO 2 sensors with high sensitivity and fast response/recovery rate.