The preparation, optical properties and applications of carbon dots derived from phenylenediamine

Carbon dots (CDs), a rising star in the field of carbon-based nanomaterials, have attracted great attention since they were discovered. Phenylenediamine C6H4(NH2)2 (PD) has high activity amino group, which enables PD to generate various oxidation products through oxidation/polymerization under suitable conditions, and these oxidation products can be further cross-linked, carbonized or polymerized to obtain CDs. Recently, CDs derived from PD have received extensive attention and research owing to their outstanding properties in regulating photoluminescence (PL) emission, excellent biocompatibility and low toxicity. Herein, the latest research progress of CDs derived from PD is summarized. A series of different preparation methods to achieve better PL performance and more advanced functions are discussed, and the formation mechanism of CDs is debated based on the difference in preparation temperature. The optical properties of CDs are explained from three perspectives: absorption, PL emission and PL mechanism. In addition, the applications of CDs for sensing, bioimaging, biomedicine, light-emitting diodes and other fields are summarized. The challenges faced and prospects for PD-derived CDs are also highlighted and discussed.