Fabrication and Characterization of Semiconductor ZnO Nanofiber for Advanced Environmental Sensing

摘要

Nanostructured semiconducting metal oxides offer an extremely high surface/volume ratio which have detecting sensitivity of part per million and even below, dynamic range and decrease the response time by more than 10-fold in comparison with thin film materials. Motivated by the recent development in fabricating and synthesizing nano-sized metal oxides, we have used an electrospinning method to produce semiconducting ZnO nanofibers for advanced environmental sensing. ZnO/PVP composite fiber mats were directly electrospun onto a SiO_2/Si at 120℃, then calcined at 600℃. Polycrystalline wurtzite ZnO nanofibers of diameter in 35～70 nm were obtained. The CO gas sensing performances have been evaluated in a CO concentration range of 10-25 ppm. The resistances of ZnO nanofibers were observed to decrease upon exposure to CO. This is attributed to the reducing nature of CO, which reacts with O~- to release an extra electron.