Full-color tunable photoluminescent carbon dots based on oil/water interfacial synthesis and their applications

Herein, we developed a facile method to produce high yield, full-color tunable photoluminescent (PL) carbon dots (CDs) at the oil/water interface. This unique synthesis method for CDs involved the use of the oil-soluble small molecule styrene as both the reactant and oil phase medium at low temperature (60 °C) through a catalytic-oxidation reaction in an aqueous system, which resulted in a high product yield (about 50 wt%). Interestingly, the hydroxy-rich CDs at the oil/water interface self-assembled into nanospheres (N-CDs) spontaneously via hydrogen-bond interactions in the presence of styrene droplets. Without any surface passivation, the N-CDs exhibited self-quenching-resistant and full-color tunable PL properties, which are highly desirable in the optoelectronic field. The mechanism of the formation of N-CDs and their emission is proposed for the first time, which provides insight into the possible chemical processes occurring during the preparation. These distinctive CDs have potential novel applications in PL coatings, smart wearable optoelectronic devices, light emitting diodes, full-color displays, and solar cells.