Enhanced Room Temperature NO₂ Sensing Performance of RGO Nanosheets by Building RGO/SnO₂ Nanocomposite System

RGO/SnO 2 nanocomposites were prepared by a simple blending method and then airbrushed on interdigitated electrodes to obtain the corresponding gas sensors. The characterizations of SEM, TEM, Raman, XRD and FTIR were used to characterize the microstructures, morphologies and surface chemical compositions of the nanocomposites, indicating that the two materials coexist in the composite films and the concentration of surface defects is affected by the amount of SnO 2 nanoparticles. It is also found that the room temperature sensing performance of RGO to NO 2 can be improved by introducing appropriate amount of SnO 2 nanoparticles. The enhanced NO 2 sensing properties are attributed to the rough surface structure and increased surface area and surface defects of the nanocomposite films. Since further reduction of RGO, heat treating the sensing films resulted in a decrease in the response and recovery times of the sensors. Furthermore, the sensor annealed at 200 ∘ C exhibited a small baseline drift, wide detection range, good linearity, high stability and better selectivity.