Green Synthesis of Carbon Dots from Grapefruit and Its Fluorescence Enhancement

Figure 5

(a) The fluorescence spectra of UCQDs (a1), NCQDs (b1), and UCQDs-peel (c1), under the different excitation wavelengths. (b) The UV–vis absorption spectra of UCQDs (a2), NCQDs (b2), and UCQDs-peel (c2).

(a)

(b)

(c)