Chemiresistive gas sensors based on thermally reduced graphene oxide for sensing sulphur dioxide at room temperature

Reduced graphene oxide (rGO) has been successfully prepared by a facile method of thermal reduction of graphene oxide in the presence of inert gas environment. The combined characterizations which include Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicate the successful formation of thermally reduced rGO. The gas sensing application of the prepared samples is demonstrated by the changes in the chemiresistive properties. The rGO based sensor is operated at the room temperature for the detection of SO2 at low part per million (ppm) levels. It is found that rGO based chemiresistive sensors exhibit sensing response of 3.21% at the concentration level of SO2 as low as 5 ppm at room temperature. The sensing response increases with increase in ppm level of the analytes and it exhibits rapid response, good selectivity and reproducibility at room temperature. Furthermore, the increase in sensing response is attributed to increase in number of defects in the sensing layer as well increase in its macroporous structure.