Carbon nanofiber/polypyrrole nanocable as toxic gas sensor

Carbon nanofiber (CNF)/polypyrrole (PPy) coaxial nanocables were successfully fabricated via one-step vapor deposition polymerization (VDP), and their capability to perceive irritant gases such as ammonia (NH3) and hydrochloric acid (HCl) was systematically examined. The Fourier transform infrared (FT-IR) spectra confirmed the formation of a PPy layer on the CNF surface. In addition, a transmission electron microscopy (TEM) image represented the formation of an ultrathin and uniform PPy layer onto the surface of CNF. The thickness of the PPy layer was conveniently controlled by varying the feeding amount of the corresponding monomer. The PPy-coated CNF exhibited an enhanced response signal due to the presence of the thin and uniform conducting polymer layer, and their response was strongly dependent on the thickness of the PPy layer.