Two-Dimensional Transition-Metal Carbides and Carbonitrides

The discovery of two-dimensional (2D) titanium carbide in 2011 opened the door for a whole family of 2D transition-metal carbides and carbonitrides, which has expanded dramatically to close to 20 different compositions since that time. Selective etching is a very well-known approach to synthesize nanomaterials such as nanogold leaves from copper–gold alloys and porous carbon from metal carbides. It can also be used to alternate the structure in case of layered materials with strong bonds in all directions in order to exfoliate its layers. An attempt to produce nanosheets of titanium and niobium carbides was reported by Chen and Bao. They used few-layer graphene as a template and reacted it with volatile titanium or niobium iodides. Theoretical calculations were used powerfully to predict properties and potential applications of MXenes. Since MXenes share very similar surface chemistries with transition-metal oxides and hydroxides, they share some surface properties.