Rapid preparation of Mo 2 CT x MXene by hydrothermal etching in ammonium hydrogen fluoride solution

In this paper, we report a novel method to rapidly prepare two-dimensional Mo 2 CT x MXene in a lowconcentration etching solution. By this method, highly pure Mo 2 CT x MXene was synthesized from Mo 2 Ga 2 C by hydrothermal etching at 180 degree celsius in the solution of ammonium hydrogen fluoride (NH 4 HF 2 ). The whole process requires only 2 h and the etching solution concentration is only 1 M. Compared with the acid solutions used in other methods, NH 4 HF 2 used in this method is in solid state and its water solution is mild for handling. Compared with other methods, this method requires a lower concentration of etching solution and a much shorter etching time. The Mo 2 CT x MXene made this method have comparable microstructure and properties with those made by other methods. The initial discharge capacity as an anode of lithium-ion batteries (LIB) was 139.35 mAh g -1 at 0.1 A g -1 . After 150th cycles, the final discharge capacity was 62.42 mAh g -1 at 0.1 A g -1 . The electrochemical performance is slightly higher than the sample made by general HF etching. This is the first report to make Mo 2 CT x MXene from the etching of bifluoride salt. Due to the short etching time and low concentration of the etching solution, this method can rapidly make Mo 2 CT x MXene at in low cost, which provides a route to explore the large-scale production of Mo 2 CT x MXene.