Stabilising intrinsic room-temperature ferromagnetic two-dimensional semimetallic Cr ₂CT x MXene by epitaxial self-intercalation of H ₂O-etched Cr ₂(AlLi)C

The physical properties, such as electrochemical and electromagnetic properties, of two-dimensional MXenes can be improved by enhancing their stability. However, MXenes fabricating via acid etching contain defects, which affect their performance on physical properties. In this study, a method to effectively remove Al residues only using water during MXene fabrication while maintaining its structural stability is proposed. The fabrication and intercalation of MXenes are controlled via epitaxial self-intercalation of H₂O-etched Cr₂(AlLi)C. Based on this mechanism, the room-temperature ferromagnetism of two-dimensional a few-layered Cr₂CTx MXene is experimentally verified, which has a specific saturation magnetisation of ~0.26 emu/g and a Curie temperature of >353 K. Calculated electronic band structure implies semimetal Cr₂CTx MXene with a band gap of 0.75 eV. This study opens up new possibilities for the research and application of industrial-scale manufacturing of MXenes and 2D semiconductors.