Electrospun soluble conductive polypyrrole nanoparticles for fabrication of highly selective n-butylamine gas sensor

Abstract

A three-dimensional and highly porous polypyrrole (PPy) film was successfully coated onto a copper interdigital electrode (Cu-IDE) surface by electrospinning of soluble PPy nanoparticles. The chemical composition of PPy nanoparticles was analyzed using X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR). The Brunauer–Emmett–Teller (BET) analysis confirmed the porous nature of PPy nanoparticles. The field emission scanning electron microscopy (FE-SEM) images of polymer coated Cu-IDE revealed that PPy nanoparticles were assembled by electrical forces to form an outstanding honeycomb-like architecture. As a proof-of-concept demonstration of the functional properties of the electrospun PPy (Es-PPy) film, the polymer coated Cu-IDE was investigated as a sensing device for gas sensor. The as-prepared Es-PPy film proved to be a viable aliphatic amines sensing material with large response, low detection limit, fast response and good repeatability at a low operating temperature of 150°C. Moreover, the sensor demonstrated an extremely high sensitivity and selectivity to n-butylamine. The calibration sensitivity to n-butylamine is up to three orders of magnitude higher than that of other common aliphatic amines. The detection limit and linear range for determination of n-butylamine were 0.42ppm and 10.54–21.08ppm, respectively. Es-PPy gas sensor exhibited good repeatability with RSD≤8% at temperature ranges 90–200°C. The response of the Es-PPy sensor to n-butylamine was compared with electrochemically and drop coated sensors and found that it has an extremely higher response. Finally, the Es-PPy gas sensor was successfully applied to real well water sample analysis.