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

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

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2024 vol. 128 p. 1393 - 1403

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.