Photochemical fluorination of graphitic carbon nitride quantum dots: Fluorescent properties, and their mechanisms

Fluorinated graphitic carbon nitride quantum dots (F-GCNQDs) with adjustable photoluminescence (PL) were prepared by a facile photochemical method using graphitic carbon nitride quantum dots (GCNQDs) powder as the precursor and XeF2 as the dopant source. It is observed that the emission peaks of the F-GCNQDs exhibit a maximal red-shift of about 8.8 nm compared to that of the GCNQDs. Density functional theory (DFT) calculations reveal that such red-shifts can be understood by the enhancement of electron-ion core interactions upon the addition of F to C, where the presence of strongly electronegative F atoms leads to a drop in the highest unoccupied energy level.