Comparison of ethanol sensitivity based on cobalt–indium combined oxide nanotubes and nanofibers

Nano sized semiconductor oxide type gas sensor has been widely studied due to its high sensitivity. Therein, one-dimensional nanostructures have attracted a lot of interests. In this work, nanofiber and nanotube of one-dimensional nano sized cobalt–indium combined oxide were fabricated by single nozzle electrospinning. The ethanol gas sensing properties of Co–In oxide nanofiber and nanotube were investigated. The morphologies were observed by scanning electron microscopy (SEM). The elementary composition was characterized by powder X-ray diffraction (XRD), and energy-dispersive X-ray spectrometry (EDS). The BET surface area of the nanotube can be calculated to be 22   m 2 /g, which is larger than 18   m 2 /g of nanofiber. The results reveal that one-dimensional nanotubes have larger sensitivity to ethanol than that of one-dimensional nanofibers. Besides, the comparison of their response and recovery curves was tested. The selectivity was also investigated. Both nanofibers and nanotubes show a fast response and excellent selectivity.