ZnO-carbon nanofibers for stable, high response, and selective H2S sensors.

ABSTRACT

Hydrogen sulfide (H2S), as a typical atmospheric pollutant, is neurotoxic and flammable even at a very low concentration. In this study, we design stable H2S sensors based on ZnO-carbon nanofibers. Nanofibers with 30.34 wt% carbon are prepared by a facial electrospinning route followed by an annealing treatment. The resulting H2S sensors show excellent selectivity and response compared to the pure ZnO nanofiber H2S sensors, particularly the response in the range of 102-50 ppm of H2S. Besides, they exhibited a nearly constant response of approximately 40-20 ppm of H2S over 60 days. The superior performance of these H2S sensors can be attributed to the protection of carbon, which ensures the high stability of ZnO, and oxygen vacancies that improve the response and selectivity of H2S. The good performance of ZnO-carbon H2S sensors suggests that composites with oxygen vacancies prepared by a facial electrospinning route may provide a new research strategy in the field of gas sensors, photocatalysts, and semiconductor devices.