3D POROUS GRAPHENE HYDROGEL FOR IMPROVED GAS SENSING PERFORMANCE AT ELEVATED TEMPERATURE

This paper reports a new high-performance NO2 and NH3 sensor using cost-effective hydrothermal synthesized graphene hydrogel (GH) with the assistance of an integrated microheater. For the first time, the microheater is exploited to enhance the selectivity of detecting NO2 by elevating the substrate temperature. In addition, the microheater is employed to greatly speed up the signal recovery process. The NO2 and NH3 gases with low concentrations down to 200 ppb and 20 ppm respectively are detected by the GH sensor effectively. importantly, the 3D GH exhibits 10 times higher sensitivity than the 2D graphene sheet counterpart, demonstrating the practical applicability of 3D GH in gas sensing.