Related Experiment Video
Updated: Jan 7, 2026
06:44
Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
3.7K
Atomistic Mechanisms of Ti3AlC2 Etching: Oxidation, Surface Stability, and Selectivity
Valentina Nesterova1, Ana-Maria Stratulat1, Walter Malone2
1Department of Materials Engineering, Auburn University, Auburn, AL, USA.
Small (Weinheim an Der Bergstrasse, Germany)
|December 26, 2025
Summary
Understanding MAX-phase etching is key to MXene properties. This study reveals etching selectivity is kinetically controlled, with aluminum extraction being facile while titanium extraction is hindered, offering insights into MXene synthesis.
Area of Science:
- Materials Science
- Surface Chemistry
- Computational Chemistry
Background:
- MXenes are 2D materials with tunable properties derived from MAX phases.
- The etching process, crucial for MXene synthesis, is not fully understood.
- Controlling etching is vital for MXene stability and application.
Purpose of the Study:
- To elucidate the atomic-level mechanisms of MAX-phase etching.
- To identify the kinetic and thermodynamic factors governing MXene formation.
- To provide a computational framework for optimizing MXene synthesis.
Main Methods:
- Thermodynamic analysis of surface reactions.
- Ab initio molecular dynamics simulations.
- Enhanced free-energy sampling techniques.
Main Results:
- Etching selectivity is kinetically controlled, not purely thermodynamic.
- Aluminum extraction from Ti3AlC2 has low energy barriers (~0.25 eV).
- Titanium extraction is kinetically hindered (0.70–2.12 eV barriers).
- Al diffusion is rate-limiting but accelerated by stress and oxidation.
- Oxygen incorporation and MXene-like terminations facilitate Al transport.
Conclusions:
- The study provides a detailed mechanistic understanding of MAX-phase etching.
- Kinetics, particularly Al extraction barriers, dictate MXene formation.
- Computational modeling offers a pathway to optimize MXene synthesis and discover new materials.
