Fig. 2. Characterization and chemical stability of COFs. (a) 13C CP-MAS solid-state NMR spectroscopy analyses of TTT–DTDA and TTT–BTDA. Inset image shows the structures of these COFs. (b) N2 adsorption–desorption isotherms for TTT–DTDA and TTT–BTDA. (c) SEM image of TTT–DTDA and (d) TTT–BTDA. (e and f) PXRD patterns of TTT–DTDA and TTT–BTDA after 36 h treatment in water and 1 N NaOH compared with as-synthesized samples.
