Recent advances in conductive polymer based nanomaterials for environmental hazardous gas detection: A review

Semiconductor resistance gas sensors have been widely studied and applied in the detection of harmful gases due to their mature technology, low cost, high response value, and rapid response/recovery, etc. Sensing materials are the core components of semiconductor resistance gas sensors. Although traditional metal oxide sensing materials have been widely used, they generally suffer from problems such as high operating temperature, high power consumption, and limited selectivity. Therefore, conductive polymers have become a research focus for the new generation of gas sensing materials due to their unique π-conjugated electronic structure, tunable molecular design, room temperature operation, and excellent processing flexibility. In this paper, we systematically review the research progress of conductive polymers such as polyaniline (PANI), polypyrrole (PPy), and poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) (PEDOT:PSS) in harmful gas detection in recent years. It focuses on analyzing the intrinsic properties of these materials and explores the mechanism and implementation methods of enhancing their sensitivity, selectivity, and stability towards typical environmental harmful gases through composite construction strategies. Meanwhile, the application progress of conductive polymers-based gas sensors for food safety, medical diagnosis, and environmental monitoring is highlighted. Finally, the development trends and challenges towards intelligent, and integrated gas sensing technology are prospected.