Effects of green solvents and surfactants on the characteristics of few-layer graphene produced by dual-frequency ultrasonic liquid phase exfoliation technique

Tyurnina, Anastasia V.; Morton, Justin A.; Kaur, Amanpreet; Mi, Jiawei; Grobert, Nicole; Porfyrakis, Kyriakos; Tzanakis, Iakovos; Eskin, Dmitry G.

Abstract

Nowadays, one of the promising methods for scalable graphene production is ultrasound-aided liquid phase exfoliation (ULPE) of graphite. Two current limiting factors of ULPE are the use of harmful solutions (such as N-Methyl-2-pyrrolidone or Dimethylformamide) and a relatively low graphene yield. In this study, we demonstrate a new dual frequency (20 kHz and 1174 kHz) ULPE approach in various eco-friendly media, which enabled us to produce various few-layer graphene (FLG) solutions of high quality. By implementing sophisticated characterisation techniques consisting of Raman spectroscopy, UV–vis spectroscopy and high-resolution electron microscopy, the final graphene flakes structure was confirmed to correlate the properties of each individual solution. The thinner (∼3 layers) and larger (∼1.5 μm2) flakes were observed while using just water, with the highest yield (11%) of smaller FLG flakes to be achieved in the mixture of water and a surfactant. In order to understand the cavitation mechanism in different solutions, the ULPE process was investigated by acoustic measurements. This study demonstrates the crucial role of ethanol (as a solvent) and surfactants as it regulates the cavitation power and intensity of the ultrasonic field and, thereby, the cavitation effectiveness. It is suggested that the mixture of water, ethanol and a surfactant is the best medium for ULPE process where a high yield of low-defective FLG flakes can be obtained in a solution stable at least for 3 months (around 80%).

Citation

Tyurnina, A. V., Morton, J. A., Kaur, A., Mi, J., Grobert, N., Porfyrakis, K., Tzanakis, I., & Eskin, D. G. (2023). Effects of green solvents and surfactants on the characteristics of few-layer graphene produced by dual-frequency ultrasonic liquid phase exfoliation technique. Carbon, 206, 7-15. https://doi.org/10.1016/j.carbon.2023.01.062

• Journal Article Type: Article
• Acceptance Date: Jan 31, 2023
• Online Publication Date: Feb 3, 2023
• Publication Date: Mar 25, 2023
• Deposit Date: Jun 26, 2024
• Publicly Available Date: Jun 28, 2024
• Journal: Carbon
• Print ISSN: 0008-6223
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 206
• Pages: 7-15
• DOI: https://doi.org/10.1016/j.carbon.2023.01.062
• Keywords: Graphene; Acoustic pressure; Ultrasonic exfoliation; Eco-friendly solution; Shock wave emission
• Public URL: https://hull-repository.worktribe.com/output/4337984