fig2

Figure 2. Physicochemical characterizations. (A) XRD patterns; (B) FT-IR spectra; (C) N₂ sorption isotherms and pore size distributions; (D) ESR spectra of the HCN and BCN. High-resolution XPS spectra of (E) C 1s, (F) N 1s of the HCN and BCN. XRD: X-ray diffraction; FT-IR: Fourier transform infrared spectroscopy; ESR: electron spin resonance spectra; XPS: X-ray photoelectron spectroscopy; HCN: crystallized carbon nitride homojunction; BCN: bulk phenazine-based C₃N₄.