Exfoliation of Al-Residual Multilayer MXene Using Tetramethylammonium Bases for Conductive Film Applications

Emi Saita; Masaki Iwata; Yuki Shibata; Yuki Matsunaga; Rie Suizu; Kunio Awaga; Jun Hirotani; Haruka Omachi

doi:10.3389/fchem.2022.841313

Exfoliation of Al-Residual Multilayer MXene Using Tetramethylammonium Bases for Conductive Film Applications

Front Chem. 2022 Mar 21:10:841313. doi: 10.3389/fchem.2022.841313. eCollection 2022.

Authors

Emi Saita¹, Masaki Iwata², Yuki Shibata², Yuki Matsunaga², Rie Suizu^{2

3}, Kunio Awaga², Jun Hirotani^{1

3}, Haruka Omachi^{2

4}

Affiliations

¹ Department of Electronics, Graduate School of Engineering, Nagoya University, Nagoya, Japan.
² Department of Chemistry, Graduate School of Science, Nagoya University, Nagoya, Japan.
³ PRESTO, Japan Science and Technology Agency, Saitama, Japan.
⁴ Research Center for Materials Science, Nagoya University, Nagoya, Japan.

Abstract

This study describes the concise exfoliation of multilayer Ti₃C₂T _x MXene containing residual aluminum atoms. Treatment with tetramethylammonium base in a co-solvent of tetrahydrofuran and H₂O produced single-layer Ti₃C₂T _x , which was confirmed via atomic force microscopy observations, with an electrical conductivity 100+ times that of Ti₃C₂T _x prepared under previously reported conditions. The scanning electron microscopy and X-ray diffraction measurements showed that the exfoliated single-layer Ti₃C₂T _x MXenes were reconstructed to assembled large-domain layered films, enabling excellent macroscale electric conductivity. X-ray photoelectron spectroscopy confirmed the complete removal of residual Al atoms and the replacement of surface fluorine atoms with hydroxy groups. Using the exfoliated dispersion, a flexible transparent conductive film was formed and demonstrated in an electrical application.

Keywords: Al etching; MXene; exfoliation; tetramethylammonium base; transparent conductive film.