The rate of oxygen reduction reaction becomes one of the most important restraining factors for the development of high-power density metal-air devices. The metal-free carbon catalyst which demonstrates lower cost and comparable electrocatalytic activity as with commercial Pt/C, which turns to be the most promising candidate for noble metal-based catalyst. Herein, a microporous and defective carbon material was synthesized by hydrothermal method and subsequently NH3 hightemperature treatment. The relatively high surface area and defect-rich features of the as-prepared carbon accelerate the oxygen reduction process, which fulfill highly efficient electrocatalytic activity with a high onset potential of -0.04 V vs. Ag/AgCl and a limited current density of 6.5 mA cm(-2). When employed as cathode material for zinc/air batteries, high electrochemical performance with a discharge voltage of 1.1 V at 50 mA cm(-2) was achieved. (C) 2017 Elsevier Ltd. All rights reserved.