Preparation of Yb-doped SnO2 hollow nanofibers with an enhanced ethanol–gas sensing performance by electrospinning

Pure and Yb-doped (0.5 wt%, 1.0 wt%, 1.5 wt%) SnO2 hollow nanofibers were synthesized by single capillary electrospinning followed by calcination at 600 °C for 2 h. The structural, morphological and elemental composition were investigated by X-ray diffraction (XRD), energy-dispersive X-ray detector (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS). The results showed that the hollow nanofibers were composed of SnO2 nanoparticles and Yb3+ ions were successfully doped into the SnO2 lattice. Most importantly, the sensors based on 1.0 wt% Yb-doped SnO2 hollow nanofibers exhibited perfect sensing performance toward ethanol with excellent selectivity, high response (170 for 500 ppm) and fast response-recovery capability (7 s for adsorption and 8 s for desorption) compared to pure SnO2 hollow nanofibers for the same ethanol concentration at 340 °C. The results obtained in this study indicate that 1.0 wt% Yb-doped SnO2 hollow nanofibers are potential candidates for fabricating effective ethanol sensors. The growth mechanism and the ethanol sensing mechanism of the hollow nanofibers were discussed in this paper.