Beyond sonication: Advanced exfoliation methods for scalable production of 2D materials

Summary

Emerging two-dimensional (2D) materials, represented by graphene, have been exhibiting superiority over conventional bulk counterparts in various fields, from electronics to catalysis. Scalable production of these 2D materials is urgently desired in order to use their advantages in real life. However, the widely adopted sonication method cannot meet this need. We first review the scalability of the production methods of 2D materials from the point of the quality-quantity trade-off in different applications. Then, we discuss the principles, recent progress made, and the pros and cons of the available laboratory exfoliation methods beyond sonication: mechanical, hydrothermal, electrochemical, laser-assisted, and microwave-assisted exfoliation. Finally, we provide a comprehensive analysis of their scalability in six aspects—production rate, exfoliation yield, quality uniformity, reproducibility, cost, and tunability—aiming to bridge the gap between academia and industry for 2D materials production.