Electrochemical fabrication and capacitance of composite films of carbon nanotubes and polyaniline

Nanoporous composite films of multi-walled carbon nanotubes (MWNTs) and polyaniline (PAn) were grown electrochemically from acidic aqueous solutions, such that the constituents were deposited simultaneously onto graphite electrodes. Scanning electron microscopy (SEM) revealed that the composite films consisted of nanoporous networks of MWNTs coated with PAn. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) demonstrated that these composite films had similar electrochemical response rates to pure PAn films, but a lower resistance and much improved mechanical integrity. The specific electrochemical capacitance of the composite films, per unit area of the original electrode, reached as high as 3.5 F cm(-2), a significantly greater value than that of 2.3 F cm(-2) for pure PAn films prepared similarly.