Fig. 2. (a) UV-Vis spectra of CDs. Inset: PL spectra at varied temperatures, namely 200 °C (red), 250 °C (green), 300 °C (blue), 350 °C (pink), 400 °C (brown). (b) AFM images of CDs in vertical and diagonal views. (c) HR-TEM images of CDs with high magnification image on adjusted square. (d) Raman spectra of CDs and raw cellulose. Inset: Photograph of CDs compared with water under UV lamp (365 nm).
