Xia, Zhenyuan and bellani, vittorio and Palermo, Vincenzo and Sun, Jinhua (2020) Electrochemical exfoliation of graphite in H2SO4, Li2SO4 and NaClO4 solutions monitored in-situ by Raman microscopy and spectroscopy. Faraday Discussions.
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Electrochemical exfoliation of graphite in H2SO4.pdf - Accepted Version Download (1MB) | Preview |
Abstract
The electrochemical exfoliation of graphite is one of the cheapest and most tunable industrial techniques to produce graphene nanosheets with tunable degree of oxidation and solubility. Anodic oxidation allows high-yield production of electrochemically exfoliated graphene oxide (EGO) in either acids or salt solutions, with the key role played by ions electrochemically driven in between the graphene sheets. This chemical intercalation is followed by a mesoscale mechanical exfoliation process, which is key for the high yield of the process, but which is still poorly understood. In this work, we use Raman spectroscopy to simultaneously monitor the intercalation and oxidation processes taking place on the surface of highly ordered pyrolytic graphite (HOPG) during electrochemical exfoliation. The mechanism of EGO formation in either acidic (0.5 M H2SO4) or neutral (0.5 M Li2SO4) electrolytes through blistering and cracking steps is discussed and described. This process is compared also to non-destructive intercalation of graphite in an organic electrolyte (1 M NaClO4 in acetonitrile). The results obtained show how high exfoliation yield and low defectivity shall be achieved by the combination of efficient, non-destructive intercalation followed by chemical decomposition of the intercalants and gas production.
| Item Type: | Article |
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| Subjects: | 500 Scienze naturali e Matematica > 540 Chimica e scienze connesse |
| Depositing User: | Vincenzo Palermo |
| Date Deposited: | 12 Oct 2020 09:56 |
| Last Modified: | 12 Oct 2020 09:56 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/20379 |
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