Delamination of Chlorine-Terminated MXene Produced Using Molten Salt Etching

MXenes produced by Lewis acid molten salt (LAMS) etching of MAX phases have attracted the community's attention due to their controllable surface chemistry. However, their delamination is challenging due to the hydrophobicity of the produced multilayer MXene and strong interactions between the halogen-terminated MXene sheets. The current delamination method involves dangerous chemicals such as n-butyllithium or sodium hydride, making scale-up difficult and limiting the practical application of this class of MXenes. In this work, we present a simple and efficient method for the delamination of MXenes from the LAMS synthesis while maintaining their surface chemistry. LiCl salt and anhydrous polar organic solvents are used for delamination. Films produced from the delaminated MXene are flexible and have an electrical conductivity of 8000 S/cm, which is maintained after a week of exposure to 95% humidity. This successful delamination, preservation of inherent surface properties, and stability under high-humidity conditions dramatically expand the range of MXene chemistries available for research and potential applications.