▎ 摘　　要

Rational design of cost-effective and efficient bifunctional oxygen electrocatalysts for sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is urgently desired for rechargeable metal-air batteries and regenerative fuel cells. Here, the Fe3C nanoparticles encapsulated in N and F codoped and simultaneously etched graphene/CNTs architecture catalyst (Fe3C@N-F-GCNTs) was synthesized by a simple yet cost-effective strategy. The as-prepared Fe3C@N-F-GCNTs exhibited excellent ORR and OER performances, with the ORR half-wave potential positive than that of Pt/C by 14 mV, and the OER overpotential lowered to 432 mV at the current density of 10 mA center dot cm(-2). In addition, the Delta E value (oxygen electrode activity parameter) increased to 0.827 V, which is comparable to the performance of the best nonprecious metal catalysts reported to date. When it was applied in a Zn-air battery as a cathode, it achieved a peak power density of 130 mW center dot cm(-2), exhibiting the potential for large-scale applications.