Improvement of the carbon monoxide gas sensing properties of polyaniline in the presence of gold nanoparticles at room temperature

Abstract In the present work, the influence of gold (Au) nanoparticles on carbon monoxide gas sensing performance of polyaniline (PAni) at room temperature was comprehensively studied. The Au/PAni nanocomposites were synthesized by the ultrasound mixing of emeraldine salt polyaniline and different amounts of Au nanoparticles colloidal solution. The analyses of field emission scanning electron microscope in conjunction with energy-dispersive X-ray spectroscopy indicated that the surface of PAni fibers was well decorated with Au nanoparticles due to the electrostatic interaction and hydrogen bonding. Then, the gas sensing performance of all sensors was investigated toward various concentrations of carbon monoxide gas ranging from 200 to 6000 ppm at room temperature. The results indicated that the 2.5 %Au/PAni sensor possesses high response(14 %–1000 ppm), low detection limit(33 ppm), the acceptable response time(180 s), wide dynamic range(200−6000 ppm) and good selectivity owing to catalytic properties of Au nanoparticles. Thus, the one-dimensional nanostructure might give a promise for high-performance sensing applications.