Amongst the different graphene fabrication techniques, bipolar electrochemistry (BPE) has been recently reported as a simple, controllable, low cost, eco-friendly, and scalable method. It consists of a wirelessly placed carbon source between two feeding electrodes subjected to direct current (DC) voltage in a deionized water bath. Although the physicochemical characteristics of produced graphene have been evaluated, the exfoliation and deposition mechanisms are still unclear. In this study, a novel modified BPE system with an electrically-connected graphite-platinum couple acting as the bipolar electrode has been designed in order to decouple and investigate the contribution of anodic/cathodic exfoliation and deposition of graphene in the BPE process. Electron microscopy and Fourier transform infrared spectroscopy results indicate that both anodic and cathodic exfoliation of graphene could take place regardless of the type of polarization; however, the morphology and deposition rate highly depend on the polarization. Furthermore, the graphene fabricated by anodic exfoliation was found to show higher levels of oxidation compared to the graphene produced by cathodic exfoliation.
Keywords: anodic polarization; bipolar electrochemistry; cathodic polarization; exfoliation; graphene.
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