Fig. 1. Synthesis conditions of ethylenediamine-modulated carbon dots (CDs) using three different carbon sources. (a) Reaction of hydroquinone and ethylenediamine, resulting in H-CDs, (b) reaction of phenol with ethylenediamine, producing P-CDs, (c) reaction of 4-(2-pyridylazo) resorcinol and ethylenediamine, resulting in R-CDs, (a–c) images of the water solution of the samples in day light and under UV light excitation which display yellow-green emission with PL QYs labelled on the graphs.
