Size Effect of Graphene Quantum Dots on Photoluminescence

High-photoluminescence (PL) graphene quantum dots (GQDs) were synthesized by a simple one-pot hydrothermal process, then separated by dialysis bags of different molecular weights. Four separated GQDs of varying sizes were obtained and displayed different PL intensities. With the decreasing size of separated GQDs, the intensity of the emission peak becomes much stronger. Finally, the GQDs of the smallest size revealed the most energetic PL intensity in four separated GQDs. The PL energy of all the separated GQDs shifted slightly, supported by density functional theory calculations.

Automated summary

High-photoluminescence graphene quantum dots were synthesized through a simple one-pot hydrothermal process and separated using dialysis bags of different molecular weights, resulting in four GQDs with varying sizes. As the size of the separated GQDs decreased, the intensity of the emission peak became stronger, with the smallest GQDs showing the most energetic PL intensity among the four separated GQDs. The PL energy of all separated GQDs shifted slightly, as supported by density functional theory calculations.