High sensitivity of flexible graphene composites decorated with V2O5 microbelts for NO2 detection

Abstract Flexible graphene composites (FGCs) decorated with V2O5 (VO) microbelts were used as sensors for NO2 detection. The performance of the flexible sensor (FS) for NO2 detection at room temperature was evaluated using two different gas concentrations, low and high (1 and 100 ppm, respectively). The FS showed a gas response for both concentrations, but it was ≈10 times higher when the NO2 gas with a concentration of 100 ppm is detected. The best response/recovery times were 19/26 s, respectively. These times are comparable with these reported for ceramic sensors operating at 250−600 °C and are 10–100 times lower than these previously reported for graphene/rGO based sensors. The FS presented saturation for the NO2 detection after 4–17 cycles of use, but their capacity for NO2 sensing was recovered after their exposure to UV light. Finally, the FS was selective because it presented a gas response to NO2 even in presence of CO2.