Platinum particles dispersed polyaniline-modified electrodes containing sulfonated polyelectrolyte for methanol oxidation

The film of polyaniline nanowires (PANI (NW)) was deposited onto the surface of stainless steel electrode through galvanostatic polymerization of aniline (ANI) and utilized for the fabrication of Pt particles loaded catalyst electrode. PANI (NW) was doped with poly (styrene sulfonic acid) (PSS) by a sequential doping-dedoping-redoping process, to result a PANI (NW)-PSS spatial matrix. UV-vis spectroscopy confirms the success of doping-dedoping-redoping process to obtain PANI (NW)-PSS. Pt particles were deposited into the film of PANI (NW) and PANI (NW)-PSS by using potentiostatic mode (-0.2 V vs. Ag/AgCl). The morphology and structure of different PANI films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). XPS results demonstrated that PANI (NW)-PSS has more positively charged nitrogens and minimum content of side products than simple PANI (NW). AES results revealed that Pt particles were distributed into the spatial regions of PANI (NW)-PSS. Cyclic voltammetry (CV) and chronoamperometry measurements were used to investigate the electrochemical properties, electrocatalytic activity and stability of PANI (NW)/Pt and PANI (NW)-PSS/Pt electrode towards oxidation of methanol. PANI (NW)-PSS/Pt electrode with a spatial distribution of Pt particles showed an improved catalytic performance towards oxidation of methanol than the PANI (NW)/Pt electrode. (C) 2008 Elsevier B.V. All rights reserved.