Electrospun ZnO-SnO Composite Nanofibers and Enhanced Sensing Properties to SF Decomposition Byproduct HS.

Hydrogen sulfide (HS) is an important decomposition component of sulfur hexafluoride (SF), which has been extensively used in gas-insulated switchgear (GIS) power equipment as insulating and arc-quenching medium. In this work, electrospun ZnO-SnO composite nanofibers as a promising sensing material for SF decomposition component HS were proposed and prepared. The crystal structure and morphology of the electrospun ZnO-SnO samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The composition of the sensitive materials was analyzed by energy dispersive X-ray spectrometers (EDS) and X-ray photoelectron spectroscopy (XPS). Side heated sensors were fabricated with the electrospun ZnO-SnO nanofibers and the gas sensing behaviors to HS gas were systematically investigated. The proposed ZnO-SnO composite nanofibers sensor showed lower optimal operating temperature, enhanced sensing response, quick response/recovery time and good long-term stability against HS. The measured optimal operating temperature of the ZnO-SnO nanofibers sensor to 50 ppm HS gas was about 250°C with a response of 66.23, which was 6 times larger than pure SnO nanofibers sensor. The detection limit of the fabricated ZnO-SnO nanofibers sensor toward HS gas can be as low as 0.5 ppm. Finally, a plausible sensing mechanism for the proposed ZnO-SnO composite nanofibers sensor to HS was also discussed.