Fig. 1

The correlative characterization of CDs, SiO_2, and SiO₂@CDs. (A) Schematic illustration of the preparation process for SiO₂@CDs; (B) TEM and SEM images; (C) FT-IR spectra; (D) XRD patterns; (E) UV-vis absorption spectra; (F) XPS spectrum; (G) Fluorescence curves; (H) Confocal laser scanning microscope of CDs, SiO₂, and SiO₂@CDs