Fig. 4. (A) UV-vis absorption and (B) PL spectra of the as-prepared CDM, CDA and CDW aqueous solution, respectively. Insets in (A) are the photographs of CDM solution under daylight and UV lamp (365 nm). (C) PL spectra of CDM at different excitation wavelengths (in 10 nm increment starting from 280 nm to 450 nm). (D) The absorption and PL spectra of CDM solution showing the Stokes shift. (E) Schematic of excitation-dependent fluorescence emitted by CDs with various surface states.
