fig4
![Macrocycle-based covalent-organic-polymer as efficient oxygen electrocatalysts for zinc-air flow batteries](https://image.oaes.cc/4279f381-bae7-4ce3-bbb8-5ef6f469ea49/cs3064.fig.4.jpg)
Figure 4. (A) ORR LSV curves of COPMCT-Co-900, COPMCP-Co-900 and COPMCZ-Co-900; (B) LSV of COPMCT-Co-900 at different rotating rates; (C) The corresponding K-L plots at various potentials, respectively; (D) I-t curves performed of COPMCT-Co-900 and Pt/C; (E) Hydrogen peroxide yield of COPMCT-Co, COPMCT-Co-900 and Pt/C; (F) Electron transfer numbers of COPMCT-Co,