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

BARRIONUEVO, SANTIAGO D.; FIORAVANTI, FEDERICO; NUÑEZ, JORGE M.; MUÑETON ARBOLEDA, DAVID; LACCONI, GABRIELA I.; BELLINO, MARTIN G.; AGUIRRE, MYRIAM H.; IBAÑEZ, FRANCISCO J.

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2024

1932-7447

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