“…Carbon dots (CDs), a new type of zero-dimensional carbon nanomaterials with an average size less than 10 nm, have drawn tremendous attention due to their excellent biocompatibility, outstanding thermal and photon stability, and stable nanoscale sizes. , Since the first discovery of the CDs, various raw materials have been employed as carbon sources to prepare the CDs, including molecular precursors (e.g., o -phenylenediamine, phloroglucinol, citric acid, and phenols), biomass precursors (e.g., cellulose, chitosan, chlorophyll, and leaves), and waste materials precursors (e.g., waste tea, waste paper, and cigarette butts). In contrast to other precursors, the biomass polymers, with excellent properties such as being nontoxic, environmentally friendly, abundant, renewable, and inexpensive, are considered as ideal carbon sources with the aim of promoting large-scale industrialization of the CDs.…”