Figure 2

Characterization of the as-synthesized Cdots (a) HRTEM images and inset is the zoom of particles. (b) XRD pattern of the Cdots. The spherical Cdots are marked by circles. (c) UV–vis absorption spectrum of the Cdots, insets are digital photos of the Cdots dissolved in water under white-light (left) and UV (365 nm) excitation (right). (d) PL spectra of the Cdots when excited at different wavelengths from 320 to 460 nm in a 20 nm increment.