Electrospun nanowebs of NiO/SnO2 p-n heterojunctions for enhanced gas sensing

Electrospun nanowebs of p-type NiO/n-type SnO2 heterojunctions were successfully fabricated using a simple electrospinning process followed by thermo-compression and subsequent calcination processes. The morphology, chemical composition and microstructure of the as-spun SnO2/NiO nanowebs were well characterized by scanning electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. After the calcination, the thinner and porous nanofibers with a high surface area were obtained. The response of the SnO2/NiO nanowebs sensor (R-a/R-g = 27.5) is 1 order of magnitude higher than that of the pure SnO2 nanowebs sensor toward 100 ppm of ethanol with average response and recovery times of similar to 2.9 and similar to 4.7 s, respectively. Furthermore, the sensor also exhibits high reproducibility and long-term stability. This facile process is versatile for the synthesis of other materials with multilayer nanowebs for different gas sensors and can be extended for various practical applications. (C) 2016 Elsevier B.V. All rights reserved.