One-step pyrolysis synthesis of ternary (P,S,N)-doped graphene as an efficient metal-free electrocatalyst for the oxygen reduction reaction.

Graphene-based materials have been regarded recently as a promising substance for electrochemical energy conversion and storage devices owing to their unique structure and extraordinary properties. Herein, an enormously facile one-step pyrolysis approach is reported for the fabrication of ternary (P,S,N)-doped graphene, which is further investigated as an efficient metal-free electrocatalyst for the oxygen reduction reaction (ORR). Furthermore, optimized ternary-doped graphene can deliver excellent ORR catalytic activity that favors the four-electron ORR process and outstanding long-term durability (90.54% current retention after 20000 s which is far superior to that of commercial Pt/C) owing to the preferable synergetic coupling effect between P, S and N. Density functional theory (DFT) calculations were performed to reveal the synergetic coupling effect between doping elements in the ORR process. This work provides an extremely simple one-step pyrolysis method for the synthesis of P,S,N-doped graphene for electrochemical energy conversion and storage devices.