Ultraviolet-Induced Gas Sensing Performance of Ag/WO₃/rGO Nanocomposites for H₂S Gas Sensors

The attention toward cost-effective and high-performance H 2 S sensors is increasing due to the growing need for physical health and environmental monitoring. In this paper, Ag/WO 3 /reduced graphene oxide (rGO) nanocomposites were synthesized by using a microwave-assisted gas–liquid interfacial method. Nanomaterials with different Ag doping contents were successfully prepared with AgNO 3 as an additive. The Ag/WO 3 /rGO sensors exhibit remarkable selectivity toward H 2 S, and the gas sensing performances of Ag-doped WO 3 /rGO gas sensors are significantly better than those of WO 3 /rGO. At 150 °C, the response value of the 10 wt % Ag/WO 3 /rGO gas sensor to 100 ppm H 2 S is 204.5, which is 7 times higher than that of WO 3 /rGO, and the response/recovery time of the sensor is 9/49 s, respectively. Additionally, the gas sensing performance of the sensor is further enhanced under ultraviolet (UV) irradiation. The response value is enhanced to 685.8, which is 3 times higher than that without UV irradiation, and the response/recovery time is reduced to 8/38 s, respectively. The sensing mechanism is also discussed. This work offers a potential application for H 2 S detection in environmental monitoring and smart healthcare.