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

Abstract

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 22 , a significantly greater value than that of 2.3 F cm 22 for pure PAn films prepared similarly.

Polyaniline-carbon nanotube composites

“…The cyclic voltammetric peak potentials of PANI-CNT composites show very small and insignificant shifts compared to those of pure PANI although there is a considerable increase in peak currents [53,66,70,71]. The absence of any change in the peak potentials suggests that the mechanism of aniline polymerization is not affected in the presence of CNT [71].…”

“…The initial attempt has been the direct electrochemical polymerization of aniline on individual CNT whiskers [25]. Another approach has been the electropolymerization of aniline from an aqueous dispersion containing aniline and CNT [53]. Sometimes, the aniline functionalized CNT has been dispersed in the electrolyte [54].…”

Increased response/recovery lifetimes and reinforcement of polyaniline nanofiber films using carbon nanotubes

“…CNTs have previously been combined with both bulk and nano PAni to improve its properties for a range of applications, including actuation and sensing [4,6,[30][31][32][33][34][35][36][37][38][39][40]. For example, Spinks et al report using CNTs to improve the tensile strength and stress loading of PAni for artificial muscles [6].…”

Comparison of surface and bulk nitrogen modification in highly porous carbon for enhanced supercapacitors

“…However, upon heat treatment to obtain NC, the mesoporous volume is recovered and even surpasses that of UC. The nitrogen in the hexamine coating may react with the carbon when heated, etching away some of the material to open up the porous structure [43]. In the micropore region shown in …”