Fig. 3

Structural characterizations of the NBE-T-CQDs. a The typical aberration-corrected HAADF-STEM image of R-NBE-T-CQDs (the inset is the corresponding high-resolution image). b The wide-area TEM image of G-NBE-T-CQDs. Scale bar, 2 nm. (The triangular projections are highlighted by white contour lines). XRD patterns (c) and FT-IR spectra (f) of NBE-T-CQDs. 1H-NMR (d), 13C-NMR (e), and C1s (g) spectra of B-NBE-T-CQDs