Enhanced gas sensing properties of V2O5 nanowires decorated with SnO2 nanoparticles to ethanol at room temperature

Abstract

V₂O₅ nanowires decorated with SnO₂ nanoparticles are prepared by two-step mild hydrothermal reaction, and the gas sensor device is fabricated by coating the nanowires as a thick film on the alumina tube. The pure V₂O₅ nanowires have almost no response to ethanol at room temperature, however, the sensitivity of V₂O₅ nanowires decorated with SnO₂ nanoparticles is 1.46 upon exposure to 1000 ppm ethanol gas. The highest sensitivity of gas sensor based on V₂O₅ nanowires decorated with SnO₂ nanoparticles to 1000 ppm ethanol is about 14, which is 2–3 times of pure V₂O₅ nanowires. The improved sensing performance of the composite is due to the increased depletion width and active sites along the nanowires, the energy gap between V₂O₅ nanowires and SnO₂ nanoparticles promotes the electrons transport. Moreover, the gas sensor based on V₂O₅ nanowires decorated with SnO₂ nanoparticles possesses a good selectivity to ethanol compared with other gases, such as CO₂, H₂O and NH₃, and the stability of gas sensing performance is quite good, which implies that it would be a good candidate in the potential application.