Highly responsive chemical sensing on NO2 at room temperature based on reduced porous graphene

We report on a high-performance room-temperature NO2 sensor based on porous and multi-defective reduced porous graphene (rPG). The rPG sebsor exhibits much higher responsivity than that of sensor made from reduced graphene oxide (rGO) without artificial nanopores, especially under lower NO2 concentration. The limit of detection of rPG sensor is as much as 28% towards 500 ppb NO2. The remarkable surface reactivity stemmed from abundant defective sites, especially edge-defective sites of nanopores, is highly responsible for the excellent responsivity and sensitivity of rPG sensor. Moreover, the unique porous structure of rPG also contributes to the outstanding gas-sensing performance by providing open gas diffusion path, and thus significantly improving the utilization of surface active sites.