Cobalt and Nitrogen Codoped Carbon Nanosheets Templated from NaCl as Efficient Oxygen Reduction Electrocatalysts

The oxygen reduction reaction (ORR) in a cathode is an essential component of many electrochemical energy storage and conversion systems. Two‐dimensional materials are beneficial for electron conduction and mass transport with high density, showing prominent electrochemical catalytic performance towards the ORR. Herein, a simple NaCl‐assisted method to synthesize cobalt–nitrogen‐doped carbon materials (CoNC), which present prominent performance towards the ORR in alkaline media, is described. The utilization of the NaCl template endows the product with a large specific surface area of 556.4 m2 g−1, as well as good dispersion of cobalt nanoparticles. CoNC‐800@NaCl (800 indicates the calcination temperature in °C) displays an excellent onset potential of 0.94 V (vs. a reversible hydrogen electrode), which is close to that of commercial Pt/C. Additionally, CoNC‐800@NaCl also exhibits better long‐term durability and methanol tolerance than that of Pt/C. The high‐performance CoNC‐800@NaCl catalyst provides a hopeful alternative to noble‐metal catalysts for the ORR in practical applications. Sprinkle of salt: Two‐dimensional cobalt–nitrogen‐doped carbon nanosheets were successfully fabricated through a simple sodium chloride assisted pyrolysis method (see figure). These nanosheets have been tested as electrocatalysts for the oxygen reduction reaction.