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

• Published in: Applied surface science Vol. 530; p. 147209
• Main Authors: Benchakar, Mohamed, Loupias, Lola, Garnero, Cyril, Bilyk, Thomas, Morais, Cláudia, Canaff, Christine, Guignard, Nadia, Morisset, Sophie, Pazniak, Hanna, Hurand, Simon, Chartier, Patrick, Pacaud, Jérôme, Mauchamp, Vincent, Barsoum, Michel W., Habrioux, Aurélien, Célérier, Stéphane
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2020; Elsevier
• Subjects: Catalysis; Chemical Sciences; Condensed Matter; Etching agent; Hydrogen evolution reaction; Inorganic chemistry; Material chemistry; Materials Science; MXene; Oxidation; Physics; Surface chemistry; Surface properties; Ti3C2Tx; MXene; Ti3C2Tx; Surface chemistry; Surface properties; Hydrogen evolution reaction; Oxidation; Etching agent; Ti 3 C 2 T x; surface chemistry; hydrogen evolution reaction; oxidation; etching agent; surface properties
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.147209

[Display omitted] •The nature of etching agent modifies the surface chemistry of Ti3C2Tx MXene.•Combined XRD, Raman and XPS for an in-depth characterization of Ti3C2Tx MXene.•HER is a probe reaction for the characterization of Ti3C2Tx surface properties.•Various properties are obtained for Ti3C2Tx depending on the synthesis conditions. 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 Ti3C2Tx, 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 FeF3/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.