In-situ one-pot synthesis of (TiZrHfNbTa)CTx MXene via molten salt CO2 capture and electrochemical conversion

Abstract

Abstract

The practicality and sustainability of conventional two-dimensional material synthesis are compromised by their dependence on hazardous HF etching and external carbon precursors, leading to complex procedures and an unmanageable carbon cycle. In this study, using mixed metal oxides as the feed stock and a LiCl-CaCl2-KCl molten salt system as the electrolyte, (TiZrHfNbTa)CTx MXene was successfully synthesized through molten salt CO2 capture, electrochemical conversion, and in-situ etching. The synthesis was carried out by electrolysis at 800℃ and 3.2 V for 12 h, followed by a 6 h holding period. (TiZrHfNbTa)AlC MAX and (TiZrHfNbTa)CTx MXene were characterized using XRD, SEM/TEM, XPS, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The results indicate that the obtained (TiZrHfNbTa)AlC MAX exhibits a polyhedral morphology, while (TiZrHfNbTa)CTx MXene exhibits a flake-like morphology, with uniform elemental distribution. By comparing the morphology of MXene prepared by this method with that of MXene prepared by other methods, it is demonstrated that the preparation of MXene by this method is feasible. In the future, it may be possible to obtain MXene with a clearer layer structure by adjusting the parameters. This approach provides a universal strategy and a new paradigm for the green synthesis and functional applications of high-entropy MXenes in the future.