Stacking-configuration-preserved Graphene Quantum Dots Electrochemically Obtained from CVD Graphene

Abstract

ESTE ES UN PREPRINT PUBLICADO EN ARXIV. FUE PUBLICADO POR LA AMERICAN CHEMICAL SOCIETY EN LA REVISTA J. PHYS. CHEM. C 2024, 128, 3, 1393–1403. PUBLICATION DATE: JANUARY 10, 2024. EL ARTÍCULO ORIGINAL SE ENCUENTRA EMBARGADO HASTA EL 11 DE ENERO 2025. The layer stacking morphology in nanocarbons is paramount for achieving new properties and outperforming applications. Here, we demonstrate that graphene quantum dots (GQDs) retained crystallinity and stacking structure from CVD graphene grown on Ni foam. Our results reveal that GQDs subdomains comprise a few layer graphene structure in 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 graphene quantum dots (GQDs) with 2-6 graphene layers in 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 multi-layer carbon structures. This work demonstrates a relatively easy electrochemical synthesis to obtain GQDs retaining the pristine and in turn, distinctive structure of graphene grown on Ni foam.