Universal Ligands for Dispersion of Two-Dimensional MXene in Organic Solvents

Tae Yun Ko; Daesin Kim; Seon Joon Kim; Hyerim Kim; Arun S Nissimagoudar; Seung-Cheol Lee; Xiaobo Lin; Peter T Cummings; Sehyun Doo; Seongmin Park; Tufail Hassan; Taegon Oh; Ari Chae; Jihoon Lee; Yury Gogotsi; Insik In; Chong Min Koo

doi:10.1021/acsnano.2c08209

Universal Ligands for Dispersion of Two-Dimensional MXene in Organic Solvents

ACS Nano. 2022 Nov 14. doi: 10.1021/acsnano.2c08209. Online ahead of print.

Authors

Tae Yun Ko¹, Daesin Kim^{1

2}, Seon Joon Kim¹, Hyerim Kim^{1

2}, Arun S Nissimagoudar³, Seung-Cheol Lee³, Xiaobo Lin⁴, Peter T Cummings⁴, Sehyun Doo^{1

2}, Seongmin Park^{5

6}, Tufail Hassan^{1

2

7}, Taegon Oh¹, Ari Chae¹, Jihoon Lee^{5

6}, Yury Gogotsi⁸, Insik In^{5

6}, Chong Min Koo^{1

2

7

7

9}

Affiliations

¹ Materials Architecturing Research Center, Korea Institute of Science and Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea.
² KU-KIST Graduate School of Converging Science and Technology, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Republic of Korea.
³ Indo-Korea Science and Technology Center, Korea Institute of Science and Technology, Bangalore 560065, India.
⁴ Department of Chemical and Biomolecular Engineering and Multiscale Modeling and Simulation Center, Vanderbilt University, Nashville. Tennessee 37235, United States.
⁵ Department of IT Energy Convergence, Korea National University of Transportation, Daehak-ro 50, Chungju, Chungbuk 27469, Republic of Korea.
⁶ Department of Polymer Science and Engineering, Korea National University of Transportation, Daehak-ro 50, Chungju, Chungbuk 27469, Republic of Korea.
⁷ School of Advanced Materials Science and Engineering, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Republic of Korea.
⁸ Department of Materials Science and Engineering and A. J. Drexel Nanomaterials Institute, Drexel University, Philadelphia, Pennsylvania 19104, United States.
⁹ School of Chemical Engineering, Sungkyunkwan University, Seobu-ro 2066, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Republic of Korea.

PMID: 36374133
DOI: 10.1021/acsnano.2c08209

Abstract

Ligands can control the surface chemistry, physicochemical properties, processing, and applications of nanomaterials. MXenes are the fastest growing family of two-dimensional (2D) nanomaterials, showing promise for energy, electronic, and environmental applications. However, complex oxidation states, surface terminal groups, and interaction with the environment have hindered the development of organic ligands suitable for MXenes. Here, we demonstrate a simple, fast, scalable, and universally applicable ligand chemistry for MXenes using alkylated 3,4-dihydroxy-l-phenylalanine (ADOPA). Due to the strong hydrogen-bonding and π-electron interactions between the catechol head and surface terminal groups of MXenes and the presence of a hydrophobic fluorinated alkyl tail compatible with organic solvents, the ADOPA ligands functionalize MXene surfaces under mild reaction conditions without sacrificing their properties. Stable colloidal solutions and highly concentrated liquid crystals of various MXenes, including Ti₂CT_x, Nb₂CT_x, V₂CT_x, Mo₂CT_x, Ti₃C₂T_x, Ti₃CNT_x, Mo₂TiC₂T_x, Mo₂Ti₂C₃T_x, and Ti₄N₃T_x, have been produced in various organic solvents. Such products offer excellent electrical conductivity, improved oxidation stability, and excellent processability, enabling applications in flexible electrodes and electromagnetic interference shielding.

Keywords: MXene; electrically conductive MXene organic ink; ligand chemistry; organic dispersion; surface functionalization; two-dimensional (2D) materials.