Synthesis and room temperature NO2 gas sensitivity of vanadium dioxide nanowire structures by chemical vapor deposition

Abstract

Vanadium dioxide (VO2) nanowire structures were synthesized by chemical vapor deposition on unpolished quartz substrates. The effects of synthesis time, from 2 h to 6 h, on VO2 nanowires structure and room temperature NO2 gas sensing properties were studied. We used field emission scanning electron microscope and X-ray diffraction to characterize the morphology and crystal structure of the nanowires. The results show that networked VO2 nanowire structure was obtained at deposition time of 4 h. The structure evolution process was related to the strong interfacial interaction and continuing growth on the rough substrate surface. We explored the sensitivity of nanowires structure to 1–5 ppm NO2 gas at room temperature. The samples at deposition time of 4 h had the highest sensitivity for the networked structure. This study provides a reference for the fabrication of high performance NO2 gas sensor based on metal oxide semiconductor nanowire structures.