Highly efficient rapid ethanol sensing based on In2−xNixO3 nanofibers

Stable solid solution In2−xNixO3 nanofibers were formed by introducing p-type NiO into n-type In2O3 via an electrospinning technique with a subsequent calcination process. The nanofibers were characterized by differential thermal and thermal gravimetric analyzer (DTA–TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Ethanol sensing properties of the as-prepared nanofibers were investigated in detail. In order to maintain the nanofibers’ one-dimensional morphologies in the sensor fabrication, a unique measurement technique was introduced for the first time. The result showed that In2−xNixO3 nanofibers exhibited significantly enhanced sensitivity, good selectivity, fast response and recovery rate (<3 s and <2 s), and excellent linearity in a relatively wide range of 1–500 ppm at a low temperature of 180 °C. These properties make the fabricated nanofibers good candidates for ethanol detection.