Stacking-Configuration-Preserved Graphene Quantum Dots Electrochemically Obtained from CVD Graphene

BARRIONUEVO, SANTIAGO; FIORAVANTI, FEDERICO; NUÑEZ, JORGE; MUÑETÓN ARBOLEDA, DAVID; LACCONI, GABRIELA I.; BELLINO, MARTIN; AGUIRRE MYRIAM; IBAÑEZ, FRANCISCO J.

Journal of Physical Chemistry C

American Chemical Society

Año: 2024 vol. 128 p. 1393 - 1403

The layer stacking morphology in nanocarbons isparamount for achieving new properties and outperformingapplications. Here, we demonstrate that graphene quantum dots(GQDs) retain crystallinity and a stacking structure from CVDgraphene grown on Ni foam. Our results reveal that GQDsubdomains comprise a few-layer graphene structure in the AB···ABand ABC···ABC stacking configuration. HR-TEM images alongwith a multiple-approach characterization (XRD, XPS, UV−vis,AFM, and ATR-IR) exhibit ∼3.0 to ∼8.0 nm crystalline GQDswith 2−6 graphene layers thick indicating a disk-shape structure.The UV−vis profiles show changes in color of the dispersion (fromcolorless to red) during and after the electrochemistry, suggesting a systematic electrooxidation of graphene into smaller, highlycrystalline, and more complex sp2/sp3 structures. Importantly, a control experiment performed under the same conditions but with agraphitic rod exhibited large, polydisperse, and multilayer carbon structures. This work demonstrates a relatively easyelectrochemical synthesis to obtain GQDs which retain the pristine and, in turn, distinctive structure of graphene grown on Ni foam.