Flexible room-temperature gas sensor based on poly (para-phenylene terephthalamide) fibers substrate coupled with composite NiO@CuO sensing materials for ammonia detection

Abstract Flexible chemiresistor-type sensor based on chemically sensitive oxide semiconductors is of great potential for wearable sensing field. It is still challenging in designing sensing materials with high electron mobility for the enhancement of sensitivity and developing flexible chemical sensors with high durability for commercial applications. Herein, we introduce that poly (para-phenylene terephthalamide) fibers, which are currently employed as substrate to support the composite NiO@CuO metal oxide semiconductors. The poly (para-phenylene terephthalamide)-NiO@CuO gas sensor exhibits excellent thermostability, with rarely changing in mass observed up to 450 °C of high temperature testing. Furthermore, a relatively low limit of detection of 46.5 ppb for NH3 is achieved at room temperature. The gas sensing mechanism of the sensing materials is interpreted via the electron-mobility-dominating gas sensing mode, in which the hole density is directly influenced via the electrons transferring between gas molecules and sensing materials. These results of the chemical gas sensor provide great promising for developing sensing materials with highly sensitivity and unlock the potential for newly-designed flexible chemiresistor-type sensor in the field of wearable sensing applications.