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