Effect of oxyfluorination on gas sensing behavior of polyaniline-coated multi-walled carbon nanotubes

Polyaniline-coated multi-walled carbon nanotubes were prepared by in situ chemical polymerization method for the novel sensing materials of ammonia gas. The thickness of the polyaniline coatings was controlled by the oxyfluorination treatment on the multi-walled carbon nanotubes. The oxyfluorination with higher oxygen content produced the more hydrophilic functional groups on the surface of multi-walled carbon nanotubes. Both the resistivity change and the response time were significantly improved with high repeatability using the more hydrophilic multi-walled carbon nanotubes which were modified with oxyfluorination.

. The introduced hydrophilic functional groups on carbon nanotubes using oxyfluorination allowed the thickness controlled polyaniline for the sensitivity of gas sensor.Highlights► Thickness controlled polyaniline coating on the surface of MWCNTs by oxyfluorination. ► The oxyfluorinated MWCNTs showed the improvement in the dispersion stability. ► Improved gas sensing sensitivity with quick response time. ► Mechanism of hydrophilic functional groups introduced electrode for gas sensing.