Electrochemical formation of Ir oxide/polyaniline composite films

The goal of this work was to attempt to electrochemically deposit a composite polyaniline (PANI) and hydrous Ir oxide (IrOx) film. Initial attempts to achieve this by their simultaneous growth in an aniline-containing sulfuric acid solution were not successful. Instead, growth first of a relatively thin IrOx film, followed by the deposition of PANI into and on this film, yielded a CV response and electrochromic behavior characteristic of the two components of the film. The fact that the main PANI redox peak, centered in the potential range over which IrOx is electrically insulating, is seen clearly at the composite film confirms that PANI grows out of the pores of IrOx and is in direct contact with the underlying Ir metal. Although the PANI component of the composite film is still susceptible to anodic degradation/dissolution, some initial stabilization may be indicated.