Novel non-covalent sulfonated multiwalled carbon nanotubes from p-toluenesulfonic acid/glucose doped polypyrrole for electrochemical capacitors

A novel and facile non-covalent process was applied to sulfonate multiwalled carbon nanotubes (MWC-NTs) with a high -SO3H loading carbonaceous (C-SO3H). Then the sulfonated multi-walled carbon nanotubes/polypyrrole nanocomposite (MWCNTs/C-SO3H/PPy) was synthesized by the in situ chemical polymerization of pyrrole on the non-covalent sulfonated MWCNTs (MWCNTs/C-SO3H) using ammonium persulfate as oxidant at low-temperature. Fourier transform infrared (FT-IR) spectra confirm the modification of MWCNTs and an existence of interaction between the -SO3H group of the modified MWCNTs and the N-H group of PPy. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), FT-IR and ultraviolet-visible (UV-vis) spectra show that uniform PPy layer coated on the side-wall of MWCNTs/C-SO3H. The electrochemical properties of the MWCNTs/C-SO3H/PPy composite were studied by cyclic voltammetry and galvanostatic charge/discharge test. The composite possesses good rate response and stable specific capacitance, the specific capacitance loss is only 3% even after the 1000 cycles. (C) 2010 Elsevier B.V. All rights reserved.