Ultrathin CNTs films produced by surfactant free dip coating using chlorosulfonic acid as working solution.
Surface area for gas interaction increased upon sonication whilst keeping film thickness unaltered.
Sensitivity as low as to 1 ppm NO2 and 7 ppm NH3 at room temperature.
5 nm thick sensor exhibited the fastest recovery and largest response as compared to 3 nm and 10 nm sensors.
Scalable, low cost and low power sensor.