Dual-nitrogen-source strategy for N-doped graphitic layer-wrapped metal carbide toward efficient oxygen reduction...

Rational design of low-cost and high-efficient non-precious-metal catalysts for oxygen reduction reaction (ORR) has drawn tremendous attention. Herein, we report a facile template-sacrificing strategy to synthesize N-doped hierarchically porous graphitic layers wrapped iron carbide (Fe₃C@NPGL). Cost-effective graphitic carbon nitride (g-C₃N₄) combined with dopamine were used as dual-nitrogen-source which provide more active sites for ORR. By virtue of abundant Fe-N coordination sites and unique porous structure of NPGL, the as-fabricated Fe₃C@NPGL exhibits excellent ORR performances with a half-wave potential of 0.87 V, a limited current density of 6.3 mA cm^-2, and a low peroxide yield (<2.5%), which outperform commercial Pt/C and most of the reported non-precious-metal catalysts. This work provides a feasible strategy to design novel ORR electrocatalysts.