The polypyrrole (PPy) nanomaterials with different morphologies were prepared via the chemical oxidative polymerization of pyrrole in the presence of acid blue AS (AS) as the dopant and surfactant. Increasing of I he feeding ratio of AS, the morphology of the resultant acid blue AS doped polypyrrole (PPy/AS) nanomaterials changed from nanoparticles to clusters of nanofibers and nanoparticles, then nanorods, compared with the microsized PPy particles prepared without AS. The PPy/AS with the morphology of the clusters of nanofibers and nanoparticles (S-3) showed the highest electrical conductivity of 20 S/cm. When the PPy/AS samples was used as the electrode materials for the supercapacitors, two redox processes were observed in the cyclic voltammograms (CV) of all the PPy/AS electrodes, corresponding to the redox couples of AS. The highest specific capacitance was found to be 427 F/g with the PPy/AS S-3 sample. (C) 2011 Elsevier B.V. All rights reserved,