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.