  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.
