Exploring efficient and inexpensive bi-functional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a critical work for developing the fuel cells and the metal-air batteries. Nitrogen-doped carbon and transition metal (Fe or Co) has been demonstrated as promising catalyst due to the synergetic effect. In this work, the CoFe alloy nanoparticles supported on N-doped carbon nanotubes (CoFe@NCNTs) are synthetized by one-step annealing the precursors, without any templates. The as-prepared materials show both extraordinary electrocatalysis activity for ORR and OER in alkaline solution: a diffusion current density of -5.53 mA cm(-2), approximate four-electron selectivity as ORR catalyst, a potential of 0.842 V at 10 mA cm(-2). Specifically, the CoFe@NCNTs present a Tafel slope of 60.16 mV dec(-1) as OER catalyst and the variance (Delta E) is below 1.017 V in 0.1 M KOH for the OER and ORR. (C) 2018 Elsevier Inc. All rights reserved.