Figure 1. Synthetic scheme and structure.

(a) Schematic of surface functionalization and molecular structures of para-substituted anilines used in the experiments. (b–d) TEM images of C-dots (b) and their polyaromatic carbon domains (c,d). The scale bars in (b,c) represent 5 and 1 nm, respectively. The area surrounded by the dotted square in c is magnified in (d). The solid hexagons in (d) represent benzene. (e) Diffraction pattern of a polyaromatic carbon domain. (f) Chemical structure of C-dots. (g,h) Atom probe tomography of C-dots before (g) and after surface functionalization (h). The scale bar represents 5 nm.