(530h) Impedancemetric High Temperature Gas Sensor Based On Electrospun Metal Oxide Nanofibers for Selective Reducing Gas Detection

A high temperature gas sensor was developed based on electrospun metal oxide nanofibers. The morphology of the nanofibers was investigated by scanning electron microscopy and transmission electron microscopy. The impedance spectroscopy of the as-prepared nanofibers based sensor was investigated in N₂ and different gas mixtures (O₂, CO, C₃H₈, CO₂, NO and SO₂ balanced by N₂ in varied concentrations) at 800 ^oC. The sensing mechanism was investigated by equivalent circuit analysis. For the first time, the sensor was operated at high frequency, in which case strong reducing gas (CO and C₃H₈) can be selectively detected with good sensitivity, and the responses from other gases can be fully eliminated. These good results suggest that the as-prepared nanofibers is a promising material for the application of high temperature sensors for reducing gas detection and impedancemetric technique is a promising approach to improve the selectivity of gas sensors by choosing an appropriate applied frequency.