Solvent‐Induced Self‐Assembly Strategy to Synthesize Multicolor Graphene Quantum Dots

Abstract There are a few reports on solvent‐induced self‐assembly behavior of graphene quantum dots (GQDs). Here, a solvent‐induced self‐assembly strategy to synthesize super‐bright multicolor GQDs with tunable emissions from blue to red is reported. The results of the study show that the GQDs have obvious intrinsic emission, i.e., blue emission, which is confirmed to originate from an emission state associated with oxygen according to a series of characterization techniques. Whereas the multicolor fluorescence caused by the solvent is dominated by the nitrogen state associated with the surface state emission. The GQDs are found to have obvious self‐assembly phenomenon under different solvents, which in turn led to the fluorescence emission of GQDs with obvious quantum size effect, achieving tunable fluorescence from green to red with the highest photoluminescence quantum yield of 98.69%. This kind of fluorescence‐tunable GQDs generated by solvent‐induced self‐assembly reveals the changes in their morphology and optical properties within different solvents, confirming the origin of the intrinsic and surface‐state emission of GQDs. Furthermore, the synthesis of GQDs with self‐assembled properties fills the research gap in the emission mechanism of GQDs.