Enhanced gas sensing performance of polythiophene film with surface engineered porous carbon

Abstract

Incorporating carbon-based materials with electrical conductivity and chemical stability is an effective and cost-efficient approach for overcoming the limitations of conjugated polymer gas sensors, such as poor sensitivity, response rate, and low stability. Porous carbon has a large surface area and superior conductivity, which can further improve its gas-sensing performance. This study presents an organic field-effect transistor (OFET) gas sensor based on a poly(3-hexylthiophene) (P3HT) film and functionalized porous carbon materials. Porous carbon derived from the carbonization of polyvinyl chloride (PVC) is subjected to various chemical treatments to introduce oxygen-containing groups, including hydroxyl (–OH), carbonyl (–CO), and carboxyl (–COOH) groups. The experimental results indicated that these functional groups markedly enhanced the performance of the sensors owing to strong interactions with the target gases. Notably, the sensor blended with HCl-treated (–OH-modified) porous carbon exhibited the highest sensitivity and selectivity towards NO₂. Furthermore, the P3HT film blended with porous carbon exhibited superior air stability and recovery performance.