fig2

Figure 2. Characterizations of HATN-COF. (A) SEM image; (B) EDS elemental mappings; (C) TEM image (inset, SAED image); (D) ¹³C SNMR spectrum and (E) FTIR spectrum. HATN: Hexaazatrinaphthylene; COF: Covalent organic frameworks; SEM: Scanning electron microscopy; EDS:Energy-dispersive X-ray spectroscopy; TEM: Transmission electron microscopy; SAED: Selected area electron diffraction; FTIR: Fourier transform infrared; SNMR: Solid-state nuclear magnetic resonance.