Enhanced formaldehyde sensing properties of hollow SnO2 nanofibers by graphene oxide

Hollow SnO2 nanofibers were prepared by electrospinning followed by calcination treatment. The carbon materials including graphene, carbon nanotubes and graphene oxide (GO) were utilized as sensitization materials to enhance the formaldehyde (HCHO) sensing properties. The results showed that the HCHO sensing properties of hollow SnO2 nanofibers were greatly improved by mixing with a small amount of GO. X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) were used to characterize their microstructures, morphologies, compositions and surface areas. The effect of GO loading amount in the nanocomposites on the sensing performances was also investigated. 1 wt% GO was the optimized loading amount and the response value reached 32 under the exposure of 100 ppm HCHO at the optimum temperature of 120 °C, which was 4 times higher than that of hollow SnO2 nanofibers. The detection limit of HCHO was as low as 500 ppb. The unique sensing properties were attributed to the synergistic effects of hollow SnO2 nanofibers and GO nanosheets network, including large specific surface area, rich functional groups and the electric regulation effects of GO.