Facile preparation of string-like composite of hollow PPy nanospheres decorated on the carbon nanotubes

A facile approach was developed for the string-like multi-walled carbon nanotubes/polypyrrole composite (CNT/PPy) with the hollow PPy nanospheres decorated on the carbon nanotubes via in situ chemical oxidative emulsion interfacial polymerization of pyrrole in the presence of the benzenesulfonate modified multi-walled carbon nanotubes (CNT–C6H4–SO3H) as both co-dopant and co-surfactant. The well-defined string-like morphology of the CNT/PPy composite was revealed by TEM. Its electrical conductivity was found to be 0.0870 S/cm, higher than that of the hollow PPy nanospheres (0.0721 S/cm). And its thermal stability was also improved by supporting with functional carbon nanotubes. Furthermore, the string-like CNT/PPy composite possessed excellent cycling stability when being used as electrode material for supercapacitor, compared with the hollow PPy nanospheres without CNTs.