NO2 sensor with a graphite nanopowder working electrode

Cheap ultrahigh sensitivity sensors find many applications, hence their development is highly desirable. Here, we report a novel amperometric gas sensor based on the system graphene–ionic liquid–graphite nanopowder that we constructed. Prepared device exhibits response of 90% towards 2 ppm of NO2 in synthetic air and 40% of relative humidity. Short response time of 40 s and recovery time of less than one minute was observed. The variation of the saturation current with the concentration of the analysed gas shows a linear dependence in the range 1–5 ppm with a slope for the calibration curve of 0.2 μA/ppm. Our results thus show that graphite nanopowder can be efficiently used in sensing applications.