Investigating the Effect of Different Fluorides on the Synthesis and Electrochemical Properties of the Ti₃C₂T_X MXene

MXenes is a family of 2D compounds (carbides, nitrides and carbonitrides) that hold enormous potential for several technological applications, particularly in energy conversion and storage due to their unique combination of structures and chemical bonds [1]. For instance, MXenes demonstrated with efficiency in hydrogen evolution reaction and high capacitance. Despite their potential uses, producing these materials with high quality lamellas efficiently exfoliated and delaminated is a challenging task. Moreover, it is essential to develop environmentally friendly routes of exfoliation and delamination of the precursor MAX phase to obtain MXenes with adequate properties since the classical routes involve the use of concentrated fluoridric acid solutions, resulting in generation of hazardous wastes. In this study, we investigated new synthesis protocols for producing the Ti₃C₂T_x MXene from the Ti₃AlC₂ MAX phase. The HF etchant was replaced by HCl and LiF solution following the MILD synthesis protocol [2]. Further, we investigated the combination of LiF with other fluorines with larger ionic radii, NaF and KF. To analyze the effect of the synthesis protocol on the MXene produced, an extensive set of characterizations was performed including XRD, SEM, XPS, HR-TEM. In addition, the electrochemical properties of the obtained MXenes were characterized by EIS and Cyclic Voltammetry. The obtained results indicated that all routes produced MXenes with good structural features and a remarkable sensitivity of the electrochemical properties with the fluorines used.<br/><br/>Acknowledgements:<br/>The authors acknowledge the financial support from FAPESP (Grants # 19/22183-6; 20/15632-6; and 22/13307-6), the CAPES/PROEX academic scholarship and CNPq (Grants: # 408984/2023-6; # 316224/2023-5). The Multiuser Central Facilities from the Federal University of ABC (CEM-UFABC) is also acknowledged for facilities access.<br/><br/>References:<br/>[1] R.M. Ronchi, J.T. Arantes, S.F. Santos, Ceramics International 45, p. 18167 (2019).<br/>[2] M. Alhabeb, K. Maleski, B. Anasori, P. Lelyukh, L. Clark, S. Sin, Y. Gogotsi, Chem. Mater., 29, 7633 (2017).