Polydopamine-derived porous carbon fiber/cobalt composites for efficient oxygen reduction reactions

Dopamine is an excellent and flexible agent for surface coating of various materials, with the high-concentration of amine groups serving as a facile stabilizer for some metallic nanoparticles. In this work, mesoporous composites of nitrogen-doped carbon fibers (NCFs) decorated with cobalt nanoparticles have been successfully fabricated via the combination of a mussel-inspired biomimetic polydopamine (PDA)-coating process using electrospun porous polystyrene fibers as templates, a simple solution deposition method and subsequent high-temperature carbonization. This rationally designed porous NCF-Co composite possesses a large surface area and numerous electrochemically active sites, which exhibits synergistically improved catalytic activity for oxygen reduction reactions (ORRs) with a relatively positive onset potential, large current density, as well as superior durability compared with the commercial platinum-carbon (Pt/C) catalyst, making it a promising noble-metal-free catalyst for practical ORR applications.