Reduced Graphene Oxide Mediated SnO2 Nanocrystals for Enhanced Gas-sensing Properties

SnO2-reduced graphene oxide (SnO2-rGO) composites were prepared via a hydro-thermal reaction of graphene oxide (GO) and SnCl2∙2H2O in the mixed solvent of ethylene glycol and water. During the redox reaction, GO was reduced to rGO while Sn2+ was oxidized to SnO2, uniformly depositing on the surface of rGO sheets. The composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectra analysis (IR) and transmission electron microscopy (TEM), respectively, and their gas sensing properties were further investigated. Compared with pure SnO2 nanoparticles, the as-prepared SnO2-rGO gas sensor showed much better gas sensing behavior in sensitivity and response-recovery time to ethanol and H2S at low concentrations. Overall, the highly sensitive, quick-responding and low cost SnO2-rGO gas sensor could be potentially applied in environmental monitoring area.