Self-assembled hierarchical micro/nano-structured PEDOT as an efficient oxygen reduction catalyst over a wide pH range

Micro/nano-structured poly (3,4-ethylenedioxythiophene) (PEDOT) has shown a broad range of potential applications in various fields. In this work, PEDOT micro/nanostructures including hollow spheres and double-layer bowls, which exhibit typical hierarchical three-dimensional micro-structures assembled from one-dimensional nanofibers, are firstly fabricated via a template-free self-assembly polymerization method. Importantly, these PEDOT microstructures can be controllably tuned by adjusting the molar ratio of monomer to oxidant. Moreover, these micro/nano-structured PEDOT exhibit high catalytic activity for oxygen reduction reaction in acid, alkaline and neutral solutions, and thus provide an alternative cheap and efficient catalytic cathode material for fuel cells or metal-air batteries.