Faster response of NO2sensing in graphene–WO3nanocomposites

Graphene-based nanocomposites have proven to be very promising materials for gas sensing applications. In this paper, we present a general approach for the preparation of graphene–WO3 nanocomposites. Graphene–WO3 nanocomposite thin-layer sensors were prepared by drop coating the dispersed solution onto the alumina substrate. These nanocomposites were used for the detection of NO2 for the first time. TEM micrographs revealed that WO3 nanoparticles were well distributed on graphene nanosheets. Three different compositions (0.2, 0.5 and 0.1 wt%) of graphene with WO3 were used for the gas sensing measurements. It was observed that the sensor response to NO2 increased nearly three times in the case of graphene–WO3 nanocomposite layer as compared to a pure WO3 layer at room temperature. The best response of the graphene–WO3 nanocomposite was obtained at 250 °C.