Ultra-safe synthesis of Mo2CTx MXene as anode for lithium-ion battery

In this paper, a green and efficient low-concentration ammonium fluoride etching strategy is developed for the synthesis of two-dimensional highly pure Mo 2 CT x MXene. Using the Mo 2 Ga 2 C MAX phase as the precursor, highly pure Mo 2 CT x MXene was prepared via hydrothermal etching with a 1 M NH 4 F aqueous solution at 160 °C for 12 h. By employing a slow-release fluorine source mechanism, the NH 4 F concentration was maintained at 1 M, significantly reducing toxicity risks and improving operational safety while providing a safe pathway for large-scale MXene production. The structural characterization of the material revealed that the as-prepared Mo 2 CT x MXene exhibits a typical two-dimensional layered structure, with microscopic morphology and crystal parameters consistent with those obtained by conventional etching methods. As an anode material for lithium-ion batteries, the Mo 2 CT x MXene delivered an initial discharge specific capacity of 873.5 mAh g −1 at a current density of 0.05 A g −1 , and retained 33.7 mAh g −1 after 100th cycles of high-rate cycling at 0.5 A g −1 . This represents the first application of a low-concentration NH 4 F etching system for preparing Mo 2 CT x MXene. The findings of this study not only enhance the safety of MXene synthesis but also provide new research directions for the development of green synthesis processes for Mo 2 CT x MXene.