The Combination of Phthalocyanines and Polymers for Electrochemically or Photoelectrochemically Induced Processes

Phthalocyanines 1-3 were used in combinations with polymers in order to investigate reduction/reoxidation of thin film electrodes, photoinduced reduction of dioxygen at the junction of thin film electrodes to an electrolyte, and dioxygen reduction in the dark (fuel cell reaction) at dispersions of phthalocyanines on carbon supports. Electrochromic reduction/reoxidation of phthalocyanines also occurs readily inside a polymer matrix if intermolecular particle contact exists. A significant photoreduction of dioxygen is observed if O₂ can form trapped states inside of the bulk of the film, with the result of enhanced photoconductivity. The kind of polymer is of striking influence. Phthalocyanines with central metals forming localized ionized states with dioxygen are active electrocatalysts for dioxygen reduction in the dark if they are finely dispersed on a carrier. The influence of both phthalocyanine and polymer component in each of the three-mentioned processes is discussed.