AUTHOR=Saita Emi , Iwata Masaki , Shibata Yuki , Matsunaga Yuki , Suizu Rie , Awaga Kunio , Hirotani Jun , Omachi Haruka 

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

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.841313

DOI=10.3389/fchem.2022.841313

ISSN=2296-2646

ABSTRACT=<p>This study describes the concise exfoliation of multilayer Ti<sub>3</sub>C<sub>2</sub>T<sub><italic>x</italic></sub> MXene containing residual aluminum atoms. Treatment with tetramethylammonium base in a co-solvent of tetrahydrofuran and H<sub>2</sub>O produced single-layer Ti<sub>3</sub>C<sub>2</sub>T<sub><italic>x</italic></sub>, which was confirmed <italic>via</italic> atomic force microscopy observations, with an electrical conductivity 100+ times that of Ti<sub>3</sub>C<sub>2</sub>T<sub><italic>x</italic></sub> prepared under previously reported conditions. The scanning electron microscopy and X-ray diffraction measurements showed that the exfoliated single-layer Ti<sub>3</sub>C<sub>2</sub>T<sub><italic>x</italic></sub> 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.</p>