Facile and fast electrospinning of crystalline ZnO 3D interconnected nanoporous nanofibers for ammonia sensing application

One-dimensional nanoporous metal oxide nanostructures have attracted great interest for their noticeable properties in gas sensor applications. In this paper, we report fabrication of crystalline sub 100 nm 3D interconnected nanoporous nanofibers with about 250 nm diameter. Theses nanostructures have high surface to volume ratio. Glycerol monostearate is used in precursor solution using electrospinning technique and then a subsequent heat treatment is performed on it by calcination process at high temperature. We achieve high crystalline structure of ZnO wurtzite phase. The fabricated crystalline ZnO interconnected nanoporous nanofiber (C–ZnO–INN) is characterized by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, energy dispersive spectroscopy, and X-ray diffraction. In addition, gas sensitivity of C–ZnO–INN is studied at room temperature. Cobalt is doped in C–ZnO–INN as a gas catalyst to increase sensitivity of the sensor. The results of the tests indicate that the sensor sensitivity is high for ammonia in the range of 1–800 ppm at room temperature. Moreover, the results show that the gas responsivity is linear to methanol, 2-propanol, acetone, acetic acid, and ammonia gases for Co doped C–ZnO–INN comparing with bare ZnO nanofibers. The C–ZnO–INN can be a best candidate for applications in diverse fields including sensor sensing or catalytic fields due to high surface to volume ratio of fabricated nanoporous nanofibers. Furthermore, it has the potential to be used in various semiconductor nanosensor applications (biosensors, high performance chemoresistive gas sensors, and etc.) because of using the facile and fast electrospinning nanoporous nanofibers fabrication method.