Colloid Approach to the Sustainable Top-Down Synthesis of Layered Materials

The successful future of 2D materials, which are crucial for accelerating technology development and societal requirements, depends on their efficient preparation in an economical and ecological way. Herein, we present a significant advance in the top-down exfoliation and dispersion method via an aqua colloid approach. We demonstrate that a broad family of natural oil-in-water emulsification agents with an elevated hydrophilic/lipophilic balance acts in the exfoliation of layered materials and the formation of their concentrated colloids. The concentration exceeds 45 g/L for exfoliated few-layered graphene sheets possessing a micrometer size. The exfoliation of carbon nanofibers provides one of the best known unsupported and N-undoped metal-free catalysts to date in the selective dehydrogenation of ethylbenzene to styrene. Other examples include aqua colloids of exfoliated/dispersed nitrides, carbides, or nanodiamonds.