title: 25th anniversary article: MXenes: a new family of two-dimensional materials.
abstract: Recently a new, large family of two-dimensional (2D) early transition metal carbides and carbonitrides, called MXenes, was discovered. MXenes are produced by selective etching of the A element from the MAX phases, which are metallically conductive, layered solids connected by strong metallic, ionic, and covalent bonds, such as Ti2 AlC, Ti3 AlC2 , and Ta4 AlC3 . MXenes -combine the metallic conductivity of transition metal carbides with the hydrophilic nature of their hydroxyl or oxygen terminated surfaces. In essence, they behave as "conductive clays". This article reviews progress-both -experimental and theoretical-on their synthesis, structure, properties, intercalation, delamination, and potential applications. MXenes are expected to be good candidates for a host of applications. They have already shown promising performance in electrochemical energy storage systems. A detailed outlook for future research on MXenes is also presented.
authors.affiliation: Department of Materials Science and Engineering and A.J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA, 19104, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Naguib
authors.forename: Vadym N
authors.initials: VN
authors.lastname: Mochalin
authors.forename: Michel W
authors.initials: MW
authors.lastname: Barsoum
authors.forename: Yury
authors.initials: Y
authors.lastname: Gogotsi
keywords: MXene; carbide; carbonitride; ceramic; two-dimensional material