Graphene-Tin Oxide Composite Nanofibers for Low Temperature Detection of NO2 and O3

In this work we investigate the detection performance of nanofibers of tin oxide (SnO₂) towards sub-0.1 ppm nitrogen oxide (NO₂) and ozone (O₃) in air. It is found that SnO₂ nanofibers are more sensitive to O₃ than to NO₂. and the optimal working temperature differs significantly between the two gases: 200 ºC (NO₂) and 350 ºC (O₃). SnO₂ nanofibers loaded with reduced graphene oxide (rGO) show higher sensitivity than nanofibers of pure SnO₂ at low temperatures and the optimal working temperature diminishes by around 150 ºC for the two gases. The air humidity does not modify the optimum working temperature of rGO-loaded SnO₂ nanofibers but it affects their sensitivity at temperatures below 150 ºC. Irradiation with UV light is a promising method to activate gas desorption from rGO-loaded SnO₂ nanofibers so that this material could be used in chemiresistive sensors for low temperature detection of air pollutants.