Bifunctional MOF-derived Co-N-doped carbon electrocatalysts for high-performance zinc-air batteries and MFCs

High cost and vulnerable stability of noble metal catalysts are the main barriers to develop the sustainable clean energy conversion and storage technology. In this work, a novel Co species/N-doped carbon (Co-N-C) derived from ZIF-67 has been designed and successfully prepared by a simple and feasible process. The ORR activities of the obtained Co-N-C with different contents of cobalt species were systematically investigated and clearly elucidated. Notably, the Co-N-C cathode exhibits a high onset-potential −0.12 V (vs. SCE) and long-tern stability in alkaline situation. Furthermore, the self-assembled Zn-air battery and microbial fuel cells (MFCs) devices coupled with Co-N-C cathode also achieve superior open-circuit potentials (Zn-air: 1.40 V, MFC: 0.45 V) and high power densities (Zn-air: 102.3 mW m −2 , MFC: 399.7 ± 10 mW m −2 ).