An eco-friendly solution for liquid phase exfoliation of graphite under optimised ultrasonication conditions. (February 2023)

• Record Type: Journal Article
• Authors: Morton, Justin A.; Kaur, Amanpreet; Khavari, Mohammad; Tyurnina, Anastasia V.; Priyadarshi, Abhinav; Eskin, Dmitry G.; Mi, Jiawei; Porfyrakis, Kyriakos; Prentice, Paul; Tzanakis, Iakovos
• Is Part Of: Carbon. Volume 204(2023)
• Page Start: 434
• Page End: 446
• Publication Date: 2023-02
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.12.070
• Languages: English
• ISSNs: 0008-6223

Abstract

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. Graphical abstract: Image 1