Dicyandiamide and iron-tannin framework derived nitrogen-doped carbon nanosheets with encapsulated iron carbide nanoparticles as advanced pH-universal oxygen reduction catalysts.

The development of an efficient and cost-effective electrocatalyst toward the oxygen reduction reaction (ORR) is of critical importance for diverse renewable electrical energy techniques. Herein, a dicyandiamide and iron-tannin framework-derived nitrogen-doped carbon nanosheet with encapsulated iron carbide nanoparticle (FeC/N-CNS) is developed. Particularly, dicyandiamide is the key to achieve this two-dimensional nitrogen-doped lamellar carbon nanosheet. Owing to the synergistic characteristics including composition and structure, the optimal catalyst exhibits the comparable or even better catalytic activity, as well as superior methanol tolerance and stability compared with platinum/carbon catalyst over the whole pH range. More notably, the current approach can be potentially extended to synthesize additional two-dimensional structured transition-metal/carbon composites for various energy conversion and storage technologies.