The world of two-dimensional carbides and nitrides (MXenes)

• Published in: Science (American Association for the Advancement of Science) Vol. 372; no. 6547
• Main Authors: VahidMohammadi, Armin, Rosen, Johanna, Gogotsi, Yury
• Format: Journal Article
• Language: English
• Published: Washington The American Association for the Advancement of Science 11.06.2021
• Subjects: Additive manufacturing; Antennas; Atomic properties; Binders; Bonding strength; Carbon nitride; Catalysis; Composition; Conductors; Crystal defects; Crystals; Dialysis; Electrochemistry; Electrochromism; Electromagnetic radiation; Energy storage; Etching; Ferromagnetism; Hybridization; Hybrids; Inks; Liquid crystals; Manufacturing; Mechanical properties; Metalloids; Metals; MXenes; Optical properties; Organic chemistry; Polymer matrix composites; Polymers; Self-assembly; Solid solutions; Storage batteries; Surface charge; Surface chemistry; Synthesis; Titanium; Transistors; Transition metals; Vapor phases; Water purification
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.abf1581

Two-dimensional (2D) materials have attracted interest because of the unusual properties that emerge in these confined structures. There is a growing family of 2D metal carbides and nitrides known as MXenes that contain an odd number of layers in which metals (M) sandwich carbon or nitrogen (X) layers. VahidMohammadi et al. reviewed the progress in synthesizing this growing library of materials. Mixed-metal combinations can be used, as well as a range of surface terminations, making it possible to tune the properties. However, there are still challenges in improving the synthesis methods and developing techniques that can be scaled up. Science , abf1581, this issue p. eabf1581 A Review outlines the development and potential applications of a wide range of 2D metal carbides and nitrides. A decade after the first report, the family of two-dimensional (2D) carbides and nitrides (MXenes) includes structures with three, five, seven, or nine layers of atoms in an ordered or solid solution form. Dozens of MXene compositions have been produced, resulting in MXenes with mixed surface terminations. MXenes have shown useful and tunable electronic, optical, mechanical, and electrochemical properties, leading to applications ranging from optoelectronics, electromagnetic interference shielding, and wireless antennas to energy storage, catalysis, sensing, and medicine. Here we present a forward-looking review of the field of MXenes. We discuss the challenges to be addressed and outline research directions that will deepen the fundamental understanding of the properties of MXenes and enable their hybridization with other 2D materials in various emerging technologies.