Synthesis and Selective Sensing Properties of rGO/Metal-Coloaded SnO2 Nanofibers

Abstract

Ternary nanocomposites containing reduced graphene oxide (rGO) and metal (Pt or Pd)-coloaded SnO2 nanofibers (NFs) have been successfully synthesized by an electrospinning method. Transmission electron microscopy and field-emission scanning electron microscopy analyses revealed the NF morphology of the synthesized products. The gas sensing properties of the synthesized materials towards 1 ppm and 5 ppm C6H6, C7H8, and CO were tested, demonstrating enhanced sensing capability of the rGO/metal (Pt or Pd)-coloaded SnO2 NF sensor compared with that of pristine or rGO-loaded SnO2 NF sensors. Furthermore, selective sensing towards either C6H6 or C7H8 can be achieved by using Pd or Pt loading, respectively. The high specific surface area due to the existence of nanograins and p-rGO/n-SnO2 heterojunctions in the NFs, nanoheterojunctions between the noble metals and SnO2, as well as a sensitizing effect of Pt and Pd were responsible for the enhanced sensing response of the rGO/metal-coloaded SnO2 NF sensors. The obtained results demonstrate the promotional effect of coloading, as well as selectivity tuning by proper choice of a noble metal, being extendable to other gas sensing materials.