Gas Sensors Based on Chemically Reduced Holey Graphene Oxide Thin Films

The nanosheet stacking phenomenon in graphene thin films significantly deteriorates their gas-sensing performance. This nanosheet stacking issue should be solved and reduced to enhance the gas detection sensitivity. In this study, we report a novel ammonia (NH(3)) gas sensor based on holey graphene thin films. The precursors, holey graphene oxide (HGO) nanosheets, were prepared by etching graphene under UV irradiation with Fenton reagent (Fe(2+)/Fe(3+)/H(2)O(2)). Holey graphene was prepared by the reduction of HGO (rHGO) with pyrrole. Holey graphene thin-film gas sensors were prepared by depositing rHGO suspensions onto the electrodes. The resulting sensing devices show excellent response, sensitivity, and selectivity to NH(3). The resistance change is 2.81% when the NH(3) level is as low as 1 ppm, whereas the resistance change is 11.32% when the NH(3) level is increased to 50 ppm. Furthermore, the rHGO thin-film gas sensor could be quickly restored to their initial states without the stimulation with an IR lamp. In addition, the devices showed excellent repeatability. The resulting rHGO thin-film gas sensor has a great potential for applications in numerous sensing fields because of its low cost, low energy consumption, and outstanding sensing performance. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-019-3060-5) contains supplementary material, which is available to authorized users.