A review of composite conducting polymer-based sensors for detection of industrial waste gases

To maintain human and environmental health, it is essential to detect toxic gases. Over the years, researchers have often focused on industrial waste gases like CO, NO₂, H₂S, and NH₃. These hazardous gases can be detected by gas sensors.The conducting polymer, which has shown tremendous promise in room-temperature chemical gas detection due to the fact that its electrical conductivity may change when exposed to oxidative or reductive gas molecules, is one promising material for this sensor. Although in some circumstances, the decreased conductivity and significant attraction to volatile organic compounds and water molecules restrict sensitivity, stability, and gas selectivity, making them unsuitable for use as gas sensors. Inorganic sensitive materials provide various advantages in gas sensors, such as high sensitivity, rapid response to low-concentration analytes, a vast surface area, and changeable surface chemistry, which may supplement the sensing capabilities of conducting polymers. Along with their synergistic effects, there is a great deal of interest in combining inorganic sensitive materials with polymers for gas detection. This review focuses on the development of composite conducting polymers as gas-sensing materials. The implications of several factors affecting sensor performance, such as responsiveness, gas concentration, reaction time, and recovery time of conducting polymers, are highlighted. The function of inorganic nanomaterials in enhancing the gas-sensing performance of conducting polymers is discussed, as well as the development of conducting-inorganic composites including metal oxides, metal, and (carbon nanotube, and graphene. A comprehensive outlook on the topic of gas sensors containing conducting polymer-inorganic composites is delivered.