Preparation and Electrochemical Performance of Externally Doped Sulfonated Polyaniline/Multiwalled Carbon Nanotube Composites

The externally doped sulfonated polyaniline (ED-SPANI) has emerged as a potential candidate for electrochemical sensors because of its unique electroactive property and water solubility. However, the lower conductivity is the major drawback for the application of ED-SPANI. Thus, this study describes a simple procedure for the fabrication of water-soluble and high conductivity composites containing ED-SPANI and multiwalled carbon nanotubes with attached carboxylic groups (c-MWCNTs) by electrostatic adsorption in aqueous colloids. The results of Fourier transform IR and Raman spectroscopy demonstrate the electrostatic interaction between the C-N+ species of the ED-SPANI structures and the COO- species of the c-MWCNTs. The incorporation of the c-MWCNTs into ED-SPANI can significantly enhance the electrical conductivity and electrochemical activity of ED-SPANI/cMWCNT composites. Furthermore, the morphology of ED-SPANI/c-MWCNT composites measured by scanning electron microscopy and atomic force microscopy indicates the presence of well-distributed tubular structures that are individually coated with ED-SPANI on the surface of the composite, in accordance with the high electrical conductivity and electrochemical properties of the composites. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3254159] All rights reserved.