An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions

Morton, J. A., Kaur, A., Khavari, M., Tyurnina, A. V., Priyadarshi, A., Eskin, D. G., Mi, J., Porfyrakis, K., Prentice, P. and Tzanakis, I. (2023) An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions. Carbon, 204, pp. 434-446. (doi: 10.1016/j.carbon.2022.12.070)

Abstract

Ultrasonic assisted liquid phase exfoliation (ULPE) is a promising method for the large scale production of 2D materials. Currently, toxic solvents such as N-Methyl-2-pyrrolidone (NMP) are commonly used for the production of graphene. In this paper four solvents; three green solvents (water, ethanol and water/ethanol) plus NMP for comparison, were sonicated and examined in terms of their bubble dynamics and acoustic emissions. Advanced fundamental analysis was conducted using high-speed imaging synchronised with acoustic pressure measurements complemented by shadowgraphic photography of the emitted shockwaves, in order to determine a suitable eco-friendly solvent medium from a cavitation bubbles dynamics perspective. Thereafter, ULPE of graphite in the optimum solvent took place for 2 h under controlled ultrasonication parameters. The produced graphene samples were characterised by employing a series of techniques consisting of Ultraviolet–visible (UV–Vis) and Raman spectroscopy as well as transmission electron microscopy (TEM). A mixture of deionised water and ethanol was shown to produce a yield twice that of pure water, comprising of high quality few layer graphene (3–5 Ls) with an average area of ∼1.15 (μm)2 and stability of ∼78% for the duration of six months. This combination is a promising eco-friendly substitute for future commercial manufacturing of graphene.

• Item Type: Articles
• Additional Information: This work has been funded by the UK Engineering and Physical Sciences Research Council (EPSRC), to the project “Sustainable and industrially scalable ultrasonic liquid phase exfoliation technologies for manufacturing 2D advanced functional materials” (EcoUltra2D), with the grant nos. EP/R031665/1; EP/R031401/1; EP/R031819/1; EP/R031975/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Prentice, Dr Paul

Creator Roles

Prentice, P.: Investigation, Writing – review and editing

• Authors: Morton, J. A., Kaur, A., Khavari, M., Tyurnina, A. V., Priyadarshi, A., Eskin, D. G., Mi, J., Porfyrakis, K., Prentice, P., and Tzanakis, I.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Carbon
• Publisher: Elsevier
• ISSN: 0008-6223
• ISSN (Online): 1873-3891
• Published Online: 29 December 2022
• Copyright Holders: Copyright © 2022 Elsevier Ltd
• First Published: First published in Carbon 204: 434-446
• Publisher Policy: Reproduced in accordance with the publisher copyright policy