fig1
![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.1.jpg)
Figure 1. (A) NMR spectra of COPMCT-Co; (B and C) HRTEM images of COPMCT-Co-900 at different scales; (D) High-resolution Co 2p XPS for COPMCT-Co-900; (E) High-resolution N 1s XPS for COPMCT-Co-900; (F) High-resolution C 1s XPS for COPMCT-Co-900. NMR: Nuclear magnetic resonance spectroscopy; COP: covalent organic polymer; HRTEM: high-resolution transmission electron microscopy; XPS: X-ray photoelectron spectroscopy.