Oral Presentation Royal Australian Chemical Institute National Congress 2026

Graphene Production by Cathodic Exfoliation in KCl Electrolyte: Comparing Graphite Foil, Natural Graphite, and Graphite Rod (138129)

Md Habibullah Dalal 1 , Nuwan Hegoda Arachchi 1 , Chong-Yong Lee 1 , Gordon Wallace 1
  1. Intelligent Polymer Research Institute, AIIM Facility, Faculty of Engineering and Information Science, University of Wollongong, Wollongong, NSW, Australia

Cathodic exfoliation has gained significant attention as a scalable and efficient technique for producing high-quality and low-defect graphene [1-4]. In this study, it is demonstrated that the choice of starting graphite material impacts the properties of the resulting graphene [5]. Three types of graphite – graphite foil, natural graphite, and graphite rod - were examined for cathodic exfoliation in 3.0 M KCl under an applied potential of −15 V. Graphite foil enables a significantly faster cathodic exfoliation process compared to the more compact structures of natural graphite and graphite rods. For the graphite foil, the cathodically exfoliated graphene exhibits a low defect density (ID/IG of 0.09, a C/O ratio of 35) with graphite exfoliation yield of 92.8%. In contrast, the exfoliated graphene from natural graphite exhibits an ID/IG of 0.15, a C/O ratio of 28, and a graphite exfoliation yield of 30.5%, whereas graphene from graphite rod exhibits an ID/IG of 0.86, a C/O ratio of 30, and a graphite exfoliation yield of 19.5%. The dense structure of natural graphite and graphite rods led to longer exfoliation times. Exfoliation of graphite rods produced few-layer graphene with the smallest sheet size, whereas natural graphite and graphite foil yielded multilayer graphene with larger sheets. This study demonstrates the feasibility of using aqueous-based cathodic exfoliation to produce graphene from various graphite sources, leading to variations in sheet thickness, size, defect density, and solvent dispersibility.

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