Single-walled carbon nanotubes (SWNT)/polyaniline (PANI) composite films with good uniformity and dispersion were prepared by electrochemical copolymerization of aniline containing well- dissolved SWNTs. Pt was dispersed on the composite films by electrodeposition technique. The presence of SWNTs and platinum in the composite film was confirmed by XRD analysis and scanning electron microscopy (SEM). Four-point probe investigations and electrochemical impedance spectroscopys (EIS) revealed that the well arrangement of PANI coated SWNTs in these films enhanced electric conductivity and facilitated the charge-transfer of the composite films. Cyclic voltammograms (CV) and chronoamperogram showed that Pt-modified SWNT/PANI composite film performed higher electrocatalytic activity and better long-term stability than Pt-modified pure PANI film toward formaldehyde oxidation. The results imply that the SWNT/PANI composite film as a promising support material improves the electrocatalytic activity for formaldehyde oxidation greatly.

Key words: single-walled carbon nanotubes, polyaniline, composite film, formaldehyde electrooxidation, electrocatalytic activity