MXene is a class of two-dimensional inorganic compounds in materials science. These materials consist of
Transition Metal carbides, nitrides, or carbon nitrides several atomic layers thick. It was first reported in 2011 that MXene materials have the metal conductivity of transition metal carbides because they have hydroxyl groups or terminal oxygen on their surfaces.
Morphologically, MXene is like a squished hydrogel between metal oxides, and it conducts electricity so well that it can replace copper and aluminum in wires, so that ions move with much less resistance.
The significance of MXene's technological breakthrough is not only to reduce the charging time of mobile phones. Professor Gao Guoqi, who is in charge of the research project, believes that the real-life application of MXene could also extend to electric vehicles and promote the popularization of such vehicles.
The synthetic MXene prepared by HF etching has an accordion-like morphology, they are multi-layered MXene (ML-MXene), or when less than 5 layers are called thin layer MXene (FL-MXene). Since the surface of MXene can be attached to functional groups, Mn+1XnTx (where T is the functional group, O, F, OH) can be named in the usual way.
MXene can be prepared by etching the
MAX phase, which usually contains fluoride ions such as hydrofluoric acid (HF), ammonium hydrogen fluoride (NH4HF2), or hydrochloric acid (HCl) with a mixture of lithium fluoride (LiF). For example, etching
Ti3AlC2 at room temperature in an HF aqueous solution can selectively remove the A atom (Al), while the surface of the carbide layer produces the terminal O, OH, and/or F atoms.
Ti4N3 is the only MXene nitride material reported to have been synthesized, and it has a different preparation method from MXene carbide material. To synthesize Ti4N3,
Max Phase Ti4AlN3 and eutectic fluorides (lithium fluoride, sodium fluoride, potassium fluoride) need to be treated at high temperatures. This method can erode aluminum, leaving multiple layers of Ti4N3, and then immersed in tetrabutylammonium hydroxide solution ultrasound, can be divided into single or thin layers (few layers).
