Sonochemical preparation and characterization of rGO/SnO2 nanocomposite: Electrochemical and gas sensing performance

The present investigation deals with solution-based sonochemical production of graphene oxide (GO) and reduced graphene oxide-SnO2 (rGO/SnO2) nanocomposite. These rGO/SnO2 nanocomposites were analysed with XRD, TEM, FTIR and UV/visible techniques. While synthesizing rGO/SnO2 nanocomposites, use of the ultrasound generated cavitational events which has evidently improved the uniform deposition of SnO2 on graphene nanosheets. These rGO/SnO2 nanocomposites were explored for their potential electrochemical as well as gas sensing applications. The cyclic voltammetry (CV) studies revealed a good electrochemical performance of rGO/SnO2 nanocomposite with a specific capacitance of 35 F/g. Further, the influence of NO2 gas concentration was investigated on rGO/SnO2 nanocomposite based sensor at various temperatures. The nanocomposite displayed the highest response of 99.9% with a very short response time of 14 s for 100 ppm concentration of NO2 gas at 150 degrees C. These sonochemically derived rGO/SnO2 nanocomposite based sensor showed excellent performance towards NO2 gas compared to other selected gases under the same conditions.