Fussy nanofibrous network of polyaniline (PANi) for NH3 detection

Fuzzy nanofibrous network of polyaniline thin film is successfully synthesized for ammonia gas detection application. The nanofiber network of polyaniline thin film is characterized using Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscope (FESEM), transmission electron microscope and optical absorption studies. Network of polyaniline is highly porous with interconnected fuzzy nanofibers having diameter typically between 70 and 75 nm. The gas sensing properties of polyaniline film are tested at room temperature (300 K). The PANi sensor showed selectivity for NH3 over H2S compared to NO2 ( S NH 3 / S H 2 S = 48 and S NH 3 / S NO 2 = 24 ). The maximum gas response of 96% was achieved with 96.88% stability for PANi films upon exposure of 100 ppm NH3 at room temperature. The response and recovery times changed significantly with the NH3 concentration. The increased NH3 concentration affected the response and recovery times; the response time decreases from 427 to 122 s with an increase in recovery time from 180 to 1245 s.