Optical properties of polymer-derived carbon dots

Luminescent carbon dots (CDs), as an emerging material class, have been actively investigated for applications in bioimaging, photocatalysis, and optoelectronic devices. Polymer materials have exhibited great potential as candidates for the preparation of CDs due to the high carbon percentage in their chemical structure and relative abundance. More importantly, chemical upcycling provides an economic approach to process polymer waste. In this article, we review synthetic routes and optical properties of CDs derived from different polymer sources, including polyethylene, polypropylene, mixed polyolefins, polystyrene, polyurethane, polyethylene terephthalate, polyethylene glycol, polylactide, polyacrylamide and polymers derived from natural resources. Applications based on the luminescent properties of these polymer-derived CDs are also briefly discussed. Though most of the current polymer-derived CDs show inferior photoluminescence quantum yields to those of small-molecule-derived CDs, there are pathways to improve the performance of polymer-derived CDs by adjusting the synthetic conditions and incorporating additives or dopants.