Highly sensitive NO2 gas sensor based on D-A type porphyrin-cobalt phthalocyanine conjugated microporous polymer

Today's society has an unprecedented demand and requirement for sensors, and the research of toxic gas sensors is its top priority. In this paper, a chemiresistive sensor for NO2 sensing based on a porphyrin-cobalt phthalocyanine-based conjugated microporous polymer (PorCoPc-CMP) was fabricated. Benefiting from the periodic intramolecular n-n type heterojunction and the sufficiently exposed active sites on the 2D sheet-like structure, the prepared chemiresistive sensor exhibited liner response in the range of 0.1-0.5 ppm with the lower limit of detection (30 ppb) and higher sensitivity (22.91 % ppm-1) than that of the monomers. Moreover, the PorCoPcCMP also possessed good selectivity, long-term stability, and excellent recovery towards the detection of NO2. This work certified the potential of conjugated microporous polymers for gas sensing applications and provided an alternative approach for the long-term detection of NO2 gas.