Hollow Polyaniline Nanofibers for Highly Sensitive Ammonia Detection Applications

A thin film sensor based on hollow polyaniline nanofibers is fabricated for ammonia sensing applications at room temperature (25 °C). Polyaniline nanotubular structures (H.PANI) are synthesized via in-situ chemical polymerization method with the inner diameter of 200–300 nm and the outer diameter of 350–450 nm. FE-SEM, FTIR, and XRD tests are performed to analyze the H.PANI structure. To investigate the effect of structure on gas sensing performances, H.PANI sensor is compared with the polyaniline powder (P.PANI) sensor. The measured LOD of H.PANI sensor is 81 ppb, which is an indication that it can be used in various applications. There is a great proton exchange between H.PANI and ammonia gas due to its high surface to volume ratio, leading to high sensitivity. The response of the H.PANI and P.PANI sensors at one ppm ammonia are about 3.36% and 1.26%, respectively.