<i>In Situ</i> Raman and Fourier Transform Infrared Spectroscopy Studies of MXene-Electrolyte Interfaces.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40489252.
- Also identified by DOI 10.1021/acsnano.5c03810 and PMC identifier 12203640.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
A comprehensive understanding of electrochemical interfaces is essential for the optimal performance of electrocatalysts, supercapacitors, and batteries. However, understanding the electrochemical behavior of MXenes during electrochemical processes by any single technique does not provide a whole picture. We achieved real-time monitoring in the complete near-mid-infrared chemical range by utilizing Raman spectroscopy (near-infrared (NIR) excitation) and Fourier transform infrared (FTIR) spectroscopy in the mid-infrared (MIR) range. The change of intramolecular O-H vibrations of MXene-confined water was monitored in real time using FTIR, while surface terminations were monitored by using Raman spectroscopy. The dynamic interplay between charge storage and the change in MXene surface chemistry was studied by employing representative electrolytes (0.5 M H<sub>2</sub>SO<sub>4</sub>, 1 M LiCl, and 6 M KOH) and comparing hydrophilic Ti<sub>3</sub>C<sub>2</sub>T<i><sub><i>x</i></sub></i> with mixed-terminations (T = O/OH/F) with hydrophobic chlorine-terminated Ti<sub>3</sub>C<sub>2</sub>Cl<sub>2</sub> MXene electrodes. <i>Ab initio</i> molecular dynamics (MD) simulations and density functional theory (DFT) calculations were used to shed light on ion insertion with a dynamic change of ion solvation and reveal the structure of the MXene-confined water.