One MAX phase, different MXenes: a guideline to understand the crucial role of etching conditions on Ti3C2Tx surface chemistry

Mohamed Benchakar (1) , Lola Loupias (1) , Cyril Garnero (1, 2) , Thomas Bilyk (2) , Claudia Morais (1) , Christine Canaff (1) , Nadia Guignard (1) , Sophie Morisset (1) , Hanna Pazniak (3) , S. Hurand (2) , Patrick Chartier (2) , Jérôme Pacaud (2) , Vincent Mauchamp (4) , Michel W. Barsoum (5) , Aurélien Habrioux (1) , Stephane Celerier (1)

1 IC2MP [Poitiers] - Institut de chimie des milieux et matériaux de Poitiers [UMR 7285]
2 PPNa - Physique et Propriétés des Nanostructures [Institut Pprime]
3 PDP - Physique des Défauts et de la Plasticité [Institut Pprime]
4 LMP - Laboratoire de métallurgie physique
5 Department of Materials Science and Engineering and A. J. Drexel Nanotechnology Institute ( Philadelfia, USA)

MXenes are a new, and growing, family of 2D materials with very promising properties for a wide variety of applications. Obtained from the etching of MAX phases, numerous properties can be targeted thanks to the chemical richness of the precursors. Herein, we highlight how etching agents govern surface chemistries of Ti 3 C 2 T x , the most widely studied MXene to date. By combining characterization tools such as X-ray diffraction, X-ray photoelectron, Raman and electron energy loss spectroscopies, scanning and transmission electron microscopies and a surface sensitive electrochemical reaction-the hydrogen evolution reaction, HER-we clearly demonstrate that the etching agent (HF, LiF/HCl or FeF 3 /HCl) strongly modifies the nature of surface terminal groups (F, OH and/or O), oxidation sensitivity, delamination ability, nature of the inserted species, interstratification, concentration of defects and size of flakes. Beyond showing how using these different characterization tools to analyze MXenes, this work highlights that the MXene synthesis routes can influence targeted applications.

Mots clés: MXene; Ti 3 C 2 T x; etching agent; surface chemistry; surface properties; oxidation; hydrogen evolution reaction

Domaines: Matériaux; Catalyse; Chimie inorganique; Science des matériaux [cond-mat.mtrl-sci]

Mohamed Benchakar, Lola Loupias, Cyril Garnero, Thomas Bilyk, Claudia Morais, et al.. One MAX phase, different MXenes: a guideline to understand the crucial role of etching conditions on Ti3C2Tx surface chemistry. Applied Surface Science, 2020, pp.147209. ⟨10.1016/j.apsusc.2020.147209⟩. ⟨hal-02904636⟩