MOF-derived Co-MOF,O-doped carbon as trifunctional electrocatalysts to enable highly efficient Zn–air batteries and water-splitting

Abstract

Abstract Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is urgently needed for high-performance Zn–air batteries and overall water splitting. Here, a facile strategy to synthesize novel Co-MOF,O-doped carbon (Co-MOF-T) based on Zn, Co-doped glucosamine and ZIF-8 by pyrolysis at temperature T was demonstrated. The prepared Co-MOF-800 showed a superior oxygen reduction reaction (ORR) activity comparable to that of commercial Pt/C catalyst. In addition, this catalyst shows great potential in the overall water splitting due to the excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) activities. Based on the trifunctional activity, the primary Zn–air batteries using a Co-MOF-800 air electrode achieved a high open-circuit voltage of 1.38 V, a specific capacity of 671.6 mAh gZn–1, and a prominent peak power density of 144 mW cm−2. Also, the rechargeable Zn–air batteries based on Co-MOF-800 air electrode could be smoothly run for 510 cycles with a low voltage gap of 0.58 V. Finally, the trifunctional Co-MOF-800 catalyst was applied to boost the electrochemical water splitting, demonstrating its promising potential as a green energy material for practical applications.