Oxygen sensing and transport properties of nanofibers of silica, bismuth doped silica and bismuth silicate prepared via electrospinning

Electrical measurements as a diagnostic tool for gas sensing application were investigated of the SiO2 nanofibers, bismuth doped SiO2 nanofibers and bismuth silicate (Bi4(SiO4)3) nanofibers, which were synthesized by electrospinning. The gas sensing devices were fabricated using thermally evaporated Ni-Cr metals on the glass substrate and then nanofibers were deposited between the contact electrodes. The performance of the sensors was evaluated by recording DC and AC measurements in an oxygen (O2) rich environment. The morphology and structural characterization of nanofibers were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Bi4(SiO4)3 nanofibers exhibited excellent oxygen sensing properties at all temperatures (25-127 °C). The rapid response time (∼49 s) and recovery time (∼9 s) with high linearity indicated that Bi4(SiO4)3 nanofibers could be a good candidate for developing practical oxygen gas sensors.