Synthesis, extraordinary properties, and applications of 2D carbides and nitrides - MXenes

More than 50 stoichiometric MX compositions and dozens of solid solutions and MXene structures with various terminations have been reported since the first report on Ti3C2Tx in 2011 [1]. The number of possible compositions is infinite if one considers solid solutions (more than 50 have been made in our lab), high-entropy MXenes, and combinations of surface terminations. New subfamilies of in- and out-of-plane ordered MXenes, oxycarbides, 2D borides, and silicides further expand the family of non-oxide 2D materials based on transition metals. They can be made using a wide variety of methods, including direct synthesis from metal chlorides and carbon sources and the selective etching of layered ceramics in aqueous etchants, molten salts, or halogen-containing gases [2]. MXenes have opened an era of computationally driven atomistic design of 2D materials, and we are just starting our journey into the world of atomistically designed materials. MXenes possess electronic, optical, mechanical, and electrochemical properties that differentiate them from other materials. MXenes are 2D building blocks for the assembled materials and devices that will power future technologies. Chemically tunable superconductivity has been demonstrated in Nb- and Mo-based MXenes. Highly nonlinear optical properties of MXenes are being explored. Several MXenes have been predicted to exhibit topological insulator behavior. MXenes are metallic conductors but with a tunable density of states at the Fermi level, like semiconductors. Moreover, their properties are tunable by design. They can be modulated using an ionotronic approach [3], leading to breakthroughs in fields ranging from optoelectronics and electromagnetic interference shielding to communication, energy storage, catalysis, sensing, and healthcare. In several applications, such as electromagnetic interference shielding and thermal insulation, MXenes have already outperformed all other materials [4]. In this talk, I’ll discuss the emerging synthesis methods of MXenes and the effect of synthesis on composition and properties. I’ll also outline prospects for applications of MXenes in electronics, healthcare, thermal management, communication, and energy generation and storage [5].

References

1. A. VahidMohammadi, J. Rosen, Y. Gogotsi, The World of Two-Dimensional Carbides and Nitrides (MXenes), Science, 372, eabf1581 (2021)

2. M. Downes, C. E. Shuck, J. McBride, J. Busa, Y. Gogotsi, Comprehensive Synthesis of Ti3C2Tx - from MAX phase to MXene, Nature Protocols, 19, 1807–1834 (2024)

3. M. Han, D. Zhang, C. E. Shuck, B. McBride, T. Zhang, R. (John) Wang, K. Shevchuk, Y. Gogotsi, Electrochemically Modulated Interaction of MXenes with Microwaves, Nature Nanotechnology, 18 (4), 373–379 (2023)

4. J. Banks, Y. Gogotsi, MXenes: Changing the World – A Conference Report and a Look into the Future, Graphene and 2D Materials, (2024)

5. Y. Gogotsi, The Future of MXenes, Chemistry of Materials, 35 (21) 8767–8770 (2023)

Yury Gogotsi is Distinguished University Professor and Charles T. and Ruth M. Bach Endowed Chair in the Department of Materials Science and Engineering at Drexel University, where he also directs the A.J. Drexel Nanomaterials Institute. He is also serving as an Adjunct Professor of Nanoelectronics at Sumy State University (Ukraine). He received his MS (1984) and PhD (1986) from Kiev Polytechnic Institute (Ukraine) and a DSc from the National Academy of Sciences of Ukraine (1995). Professor Gogotsi is internationally recognized for pioneering contributions to nanomaterials, electrochemical energy storage, and water desalination. His work includes the first microscopic observation of confined water in carbon nanotubes, the discovery of polygonal nanotubes, and major advances in high-pressure surface science. Currently, he is best known as a co-discoverer of MXenes, a large family of two-dimensional carbides and nitrides now applied in energy storage, electronics, sensing, and environmental technologies.