fig3

Figure 3. Characterizations and acid-alkali tolerance test of HATN-COF. XPS analysis, (A) survey spectrum and the high-resolution (B) C 1s; and (C) N 1s spectra; (D) Raman spectrum; (E) XRD patterns and (F) FTIR spectrum of HATN-COF after soaking in 6 M HCl and 6 M KOH for seven days. HATN: Hexaazatrinaphthylene; COF: Covalent organic frameworks; XPS: X-ray photoelectron spectroscopy; XRD: X-ray diffraction; FTIR: Fourier transform infrared.