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 m2/g, which is larger than 18 m2/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.