Conducting polymer alloys for photo-enhanced electro-catalytic oxygen reduction

Electro-catalysis is a core element in many technologies proposed for energy storage and conversion in a post-petroleum energy landscape. This has prompted the development of new electro-catalysts, for example for fuel-cells, water-splitting cells, and metal-air batteries, which are not based on traditional rare metals such as platinum, palladium and iridium. In this context, the possibility to use organic conjugated polymers to replace inorganic catalysts has shown promising progress. We hereby demonstrate that an "alloy" of two conjugated polymers, poly[3,4-ethylenedioxythiophene] and polythiophenes, with different oxidation states can act as a photo-enhanced reduction catalyst for the oxygen reduction reaction and thereby reduce the overpotential for that reaction by more than 600 mV under illumination.