Polyaniline/carbon nanotube multi-layered hollow microspheres with sandwich structure and their electrochemical performance

Novel composite hollow microspheres with the unique "sandwich" structure were prepared by alternate coverage of polyaniline (PANI) and carboxyl-functionalized multi-walled carbon nanotubes (f-MWNTs) on the surface of spherical templates, formed by in situ polymerization. It was proved that the incorporation of f-MWNTs into the PANI layers could strengthen the stability of hollow microspheres, which had been demonstrated by other researchers in the preparation of carbon nanotubes-based hollow microcapsules. Specially, Raman spectra revealed that the driving force for adsorbing f-MWNTs was not electrostatic interaction, but hydrogen bond and additional π-π conjugated interaction. With the measurements of conductivity and electrochemical performance, it was also proved that the facile strategy to introduce f-MWNTs into the shells could effectively improve conductivity and electrochemical performance of PANI hollow microspheres.