An in situ electrospinning route to fabricate NiO–SnO2 based detectors for fast H2S sensing

Hydrogen sulfide (H2S) is a toxic and flammable chemical, even in low concentration. In this study, an in situ electrospinning strategy was developed to directly deposit the sensitive materials of nickel oxide (NiO)-doped SnO2 nanofiber on alumina substrates, resulting in the fast H2S detection. The electrospun fiber could be deposited on to the alumina tube directly, and remain there during calcination. Using this method, the NiO-doped SnO2 nanofibers fabricated and manifested a fast response, fast recovery, and high selectivity at a low temperature (150 °C). A 15% atom NiO-doped SnO2 nanofiber-containing H2S detector presented a high response (1352), low response time (23 s), and low recovery time (38 s) while detecting a concentration of 50 ppm H2S at 150 °C. Compared to conventional methods, the H2S detector based on the in situ electrospinning method showed a higher sensitivity, faster response, and faster recovery. Furthermore, the superior performance of the detector can be ascribed to the thinner film and non-interrupted fiber structure. Additionally, the transformation of NiO to Ni3S2, confirmed by the x-ray photoelectron spectroscopy under a H2S atmosphere, suggested the main reason for the detector’s high performance. The high performance of the NiO-doped SnO2 suggests a strategy for gas detectors, biodetectors, and semiconductor devices.