Dalal Md Habibullah, Arachchi Nuwan Hegoda, Lee Chong-Yong, Wallace Gordon G
Intelligent Polymer Research Institute, AIIM Facility, Faculty of Engineering and Information Science, University of Wollongong, Wollongong, NSW 2500, Australia.
Molecules. 2025 Jul 28;30(15):3151. doi: 10.3390/molecules30153151.
Cathodic exfoliation of graphite has emerged as an attractive method to synthesize high-quality and lo- defect graphene. Here, it is demonstrated that the type of starting graphite material influences the properties of exfoliated graphene. Graphite foil, natural graphite, and graphite rods were examined in the exfoliation processes performed in 3.0 M KCl at -15 V. The use of a graphite foil facilitates the rapid cathodic exfoliation process in comparison with structurally more compact natural graphite and graphite rods. For the graphite foil, the cathodically exfoliated graphene exhibits a low defect density (/ 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 / of 0.15, a C/O ratio of 28, and a graphite exfoliation yield of 30.5%, whereas graphene from graphite rod exhibits an / 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.
石墨的阴极剥离已成为一种合成高质量、低缺陷石墨烯的有吸引力的方法。在此，证明了起始石墨材料的类型会影响剥离石墨烯的性能。在3.0 M KCl中于-15 V进行的剥离过程中，对石墨箔、天然石墨和石墨棒进行了研究。与结构更致密的天然石墨和石墨棒相比，使用石墨箔有助于快速的阴极剥离过程。对于石墨箔，阴极剥离的石墨烯具有低缺陷密度（I为0.09，C/O比为35），石墨剥离产率为92.8%。相比之下，天然石墨剥离的石墨烯I为0.15，C/O比为28，石墨剥离产率为30.5%，而石墨棒剥离的石墨烯I为0.86，C/O比为30，石墨剥离产率为19.5%。天然石墨和石墨棒的致密结构导致剥离时间更长。石墨棒的剥离产生了层数最少、片尺寸最小的石墨烯，而天然石墨和石墨箔产生了片尺寸更大的多层石墨烯。本研究证明了使用水基阴极剥离从各种石墨源生产石墨烯的可行性，这导致了片厚度、尺寸、缺陷密度和溶剂分散性的变化。
