The lack of well performing, atom economical electrocatalyst for oxygen evolution reaction (OER) in water electrolyser and rechargeable metal air battery remains the impediment in their ubiquitous application. Nickel oxide...

No abstract

No abstract

The successful commercialization of rechargeable zinc-air batteries requires an inexpensive and stable bifunctional oxygen electrocatalyst which can efficiently facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction(OER). Here, we report a simple and effective route to introduce nitrogen functionalities coordinated with Fe to generate ORR active Fe-N4 species. Fe-N-C catalytic sites are known to play an active role toward ORR; however, the higher oxidation state of Fe has been speculated to be good for OER. This method generates a mixture of ORR active and OER active phases. The superior ORR activity of the catalyst, prepared by annealing at 800°C consists of the mixed phases of Fe-N4, Fe3O4, and Fe3C. The oxygen bifunctional activity measured in terms of ΔE value (1.06 V) makes it suitable for the cathode of aqueous zinc-air battery. The catalyst remains stable for approximately 63 hours of continuous charging-discharging cycles with a high specific capacity of 689 mAh g-1 with a constant charge-discharge voltage gap.