Room-Temperature 2H-WSe2/rGO Composite-Based NO2 Gas Sensor With Long-Term Stability

Herein, we present interdigitated microelectrode nitrogen dioxide (NO2) gas sensor by utilizing layered nanosheets of tungsten diselenide (2H-WSe2) intercalated with reduced graphene oxide (rGO). The 2H-WSe2 nanosheets and its composite with rGO were prepared through simple solvothermal process, resulting in intercalation with rGO sheets. Comprehensive investigation of gas-sensing properties of WSe2-rGO (WSR) composite nanosheets with their high selectivity and sensitivity to NO2 detection at ambient temperature have been performed. The WSR sensor achieved notable responses of ~2.9%, ~25.9%, and ~39% at NO2 concentrations of 50 ppb, 1 ppm, and 4 ppm, respectively. Furthermore, the sensor efficiently maintained good response of ~30.8% to NO2 gas even after 210 days of testing, demonstrating its outstanding long-term stability.