Polyaniline Nanofibers Based Gas Sensor for Detection of Volatile Organic Compounds at Room Temperature

In the present study, toluene gas sensor was developed by depositing the film of polyaniline nanofibers (PANI NFs) on silicon substrate. PANI NFs were synthesized by in situ chemical oxidative polymerization method using aniline as monomer. PANI NFs were confirmed by the x-ray Diffraction (XRD), Fourier Infrared Transform Spectroscopy (FTIR), Field - Emission Scanning Electron Microscope (FE-SEM) and High Resolution-Transmission Electron Microscope (HR-TEM). The FE-SEM and HR-TEM were showed that interconnected nanofibers structure of the PANI particles. The diameters of the PANI NFs were measured in range 70–80 nm and length in 400–450 nm. These PANI NFs were explored for the volatile organic compounds (VOCs) sensing such as toluene, ethanol, chloroform, acetone and methanol in the concentration ranging from 50 ppm to 1000 ppm. PANI NFs based sensor was observed to be selective for low concentration of toluene than all VOCs tested. Sensitivity of the PANI NFs sensor found to be 24.5% for 50 ppm for toluene gas. The response and recovery time for toluene (400 ppm) were observed to be 92 s and 120 s, respectively. The PANI NFs sensor was observed to be stable for 45 days.