Sensitive detection of nitrogen dioxide gas at room temperature using poly(3,4-ethylenedioxythiophene) nanotubes

Abstract

In the present work, we report on room temperature sensing of nitrogen dioxide (NO2) gas using nanotubes made of intrinsically conducting poly(3,4-ethylenedioxythiophene) (PEDOT). The nanotubes of PEDOT (PEDOT-NT) were prepared by reverse emulsion polymerization method and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and Fourier transformation infrared spectroscopy (FTIR). The thin film of PEDOT-NT on prefabricated gold interdigitated electrodes (IDEs) was obtained by drop drying the suspension of PEDOT-NT in N,N′-dimethylformamide. The PEDOT-NT coated IDE sensor showed good response towards sensing NO2 at room temperature. The recovery of the sensor was accelerated by ultra-violet light illumination. The proposed sensor showed excellent characteristics such as high sensitivity (1.316%/ppm), low detection limit of 80ppb (at S/N=3) and linear concentration range of 0.2–20ppm for sensing NO2 gas. The proposed sensor also showed excellent selectivity in respect of interfering gases such as H2S, NH3, SO2, CO, ethanol, acetone and benzene.