As a kind of metal-free polymer, graphitic carbon nitride (g-C3N4) has captivated considerable attention. In this work, an efficient one-pot, economical and green pathway was investigated to simultaneously prepare highly fluorescent g-C3N4 quantum dots (g-C3N4 QDs) and ultrathin g-C3N4 nanosheets via ethanol-thermal treatment of bulk g-C3N4 in the presence of KOH. The as-obtained g-C3N4 QDs exhibited narrow particle size distribution with an average diameter of 3.3 ± 0.3 nm. Benefiting from these alluring properties, such as excellent water solubility, bright blue fluorescence, favorable stability and good biocompatibility, the g-C3N4 QDs were successfully employed as a brand-new but promising candidate for bioimaging in vitro. Furthermore, this convenient strategy would open a new avenue for the large-scale synthesis of other layered materials.
