Electrospinning Hetero-Nanofibers In₂O₃/SnO₂ of Homotype Heterojunction with High Gas Sensing Activity.

In₂O₃/SnO₂ composite hetero-nanofibers were synthesized by an electrospinning technique for detecting indoor volatile organic gases. The physical and chemical properties of In₂O₃/SnO₂ hetero-nanofibers were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Energy Dispersive X-Ray Spectroscopy (EDX), specific surface Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS). Gas sensing properties of In₂O₃/SnO₂ composite hetero-nanofibers were measured with six kinds of indoor volatile organic gases in concentration range of 0.5~50 ppm at the operating temperature of 275 °C. The In₂O₃/SnO₂ composite hetero-nanofibers sensor exhibited good formaldehyde sensing properties, which would be attributed to the formation of n-n homotype heterojunction in the In₂O₃/SnO₂ composite hetero-nanofibers. Finally, the sensing mechanism of the In₂O₃/SnO₂ composite hetero-nanofibers was analyzed based on the energy-band principle.