Rapid preparation of Mo2CTx MXene by hydrothermal etching in ammonium hydrogen fluoride solution

Abstract

In this paper, we report a novel method to rapidly prepare two-dimensional Mo2CTx MXene in a low-concentration etching solution. By this method, highly pure Mo2CTx MXene was synthesized from Mo2Ga2C by hydrothermal etching at 180 ℃ in the solution of ammonium hydrogen fluoride (NH4HF2). 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, NH4HF2 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 Mo2CTx 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 Mo2CTx 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 Mo2CTx MXene at in low cost, which provides a route to explore the large-scale production of Mo2CTx MXene.