ZIF-8/LiFePO4 derived Fe-N-P Co-doped carbon nanotube encapsulated Fe2P nanoparticles for efficient oxygen reduction and Zn-air batteries

Iron-based oxygen reduction reaction (ORR) catalysts have been the focus of research, and iron sources play an important role for the preparation of efficient ORR catalysts. Here, we successfully use LiFePO4 as ideal sources of Fe and P to construct the heteroatom doped Fe-based carbon materials. The obtained Fe-N-P co-doped coral-like carbon nanotube arrays encapsulated Fe2P catalyst (C-ZIF/LFP) shows very high half-wave potential of 0.88 V in alkaline electrolytes toward ORR, superior to Pt/C (0.85 V), and also presents a high half-wave potential of 0.74 V in acidic electrolytes, comparable to Pt/C (0.8 V). When further applied into a home-made Zn-air battery as cathode, a peak power density of 140 mW·cm2 is reached, exceeds commercial Pt/C (110 mW·cm2). Besides, it also presents exceptional durability and methanol resistance compared with Pt/C. Noticeably, the preparation method of such a high-performance catalyst is simple and easy to optimize, suitable for the large-scale production. What's more, it opens up a more sustainable development scenario to reduce the hazardous wastes such as LiFePO4 by directly using them for preparing high-performance ORR catalysts.