An innovative gas sensor system designed from a sensitive organic semiconductor downstream a nanocarbonaceous chemical filter for the selective detection of NO2 in an environmental context

Abstract

Abstract An original gas sensor system dedicated to the selective monitoring of nitrogen dioxide in air has been successfully developed. This device combines the great sensitivity and the partial selectivity toward oxidizing gases of a molecular organic semiconductor, copper phthalocyanine, with the O3 filtering capability of different carbonaceous nanomaterials located upstream the sensitive layer in the gas flux. The carbonaceous materials are used either as-prepared or modified by physical or chemical treatments. The ability to filter nitrogen dioxide and ozone, has been correlated to both the BET specific surface area determined by N2 adsorption at 77 K and the presence of chemical functional groups at the surface. A sensing structure is finally proposed using a chemical filter containing nanocarbons, impermeable to ozone and inert toward nitrogen dioxide, leading to a selective NO2 sensor response.