Morphology and Electronic Properties of Electrochemically Exfoliated Graphene

Abstract

Electrochemically exfoliated graphene (EEG) possesses optical and electronic properties that are markedly different from those of the more explored graphene oxide in both its pristine and reduced forms. EEG also holds a unique advantage compared to other graphenes produced by exfoliation in liquid media: it can be obtained in large quantities in a short time. However, an in-depth understanding of the structure-properties relationship of this material is still lacking. In this work, we report physicochemical characterization of EEG combined with an investigation of the electronic properties of this material carried out both at the single flake level and on the films. Additionally, we use for the first time microwave irradiation to reduce the EEG and demonstrate that the oxygen functionalities are not the bottleneck for charge transport in EEG, which is rather hindered by the presence of structural defects within the basal plane.

Production and Patterning of Liquid Phase–Exfoliated 2D Sheets for Applications in Optoelectronics

“…While the former allows the estimation of the number of layers of exfoliated ( N L ) sheets by counting the number of sheet's edges and by using electron diffraction patterns, the latter enables the estimation of N L by measuring the height of the flakes and dividing it by the corresponding interlayer distance . Yet, it is important to note that the estimation of SL flakes height via AFM varies with the nature of the substrate (e.g., roughness, hydrophobicity, or hydrophilicity) and depends on the magnitude of the force applied by the tip to the sample as well as the experimental conditions such as relative humidity . Nevertheless, AFM can be employed to gain in‐depth insight into the surface morphology of exfoliated flakes of 2DMs, as shown in Figure a,d for graphene and h ‐BN, respectively.…”

“…Nevertheless, AFM can be employed to gain in‐depth insight into the surface morphology of exfoliated flakes of 2DMs, as shown in Figure a,d for graphene and h ‐BN, respectively. Moreover, AFM can reveal the presence of structural defects on the surface of SL graphene flake (Figure b) …”

High‐Performance Graphene‐Based Cementitious Composites

“…[41][42][43][44] In general, the oxidation of graphene sheets is unavoidable during anodic EE, and it depends on both the exfoliation time and the type of employed electrolyte, which in some cases can prevent extensive oxidation. [41][42][43][44] In general, the oxidation of graphene sheets is unavoidable during anodic EE, and it depends on both the exfoliation time and the type of employed electrolyte, which in some cases can prevent extensive oxidation.…”

“…[41][42][43][44] In general, the oxidation of graphene sheets is unavoidable during anodic EE, and it depends on both the exfoliation time and the type of employed electrolyte, which in some cases can prevent extensive oxidation. [44] Noteworthy, during the electrolysis process, the area of the working electrode (graphite foil) is reduced, determining a variation of the current intensity passing between the electrodes. In particular, an electrolysis process lasting 180 min allows production of ≈200 mg of EEG, whereas classical EE lasting for 10 min results in ≈10 mg of EEG.…”

Flexible Planar‐Integrated Micro‐Supercapacitors from Electrochemically Exfoliated Graphene as Advanced Electrodes Prepared by Flash Foam–Assisted Stamp Technique on Paper

“…In addition, the use of harmful and explosive substances is prone to bring safety hazards and environmental pollution problems. Because of its simple, reliable, and environmentally friendly properties, the electrochemical exfoliation of graphite has been widely favored by the researchers around the world recently, which is based on using ion insertion of electrolytes to prepare graphene sheet dispersion . Most importantly, this method reduces the damage to the graphene structure.…”