Computationally Guided Synthesis of MXenes by Dry Selective Extraction

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• 2D transition metal carbides and nitrides (MXenes) show promise for energy storage, electronics, and healthcare.
• Current synthesis methods using hydrofluoric acid produce mixed surface terminations, hindering MXene properties.
• Scalable and controlled synthesis of MXenes with specific surface chemistries is highly desired.

Purpose of the Study:

• To explore fluorine-free synthesis of MXenes with uniform surface terminations.
• To develop and validate a computational thermodynamic model for predicting MXene synthesis conditions.
• To enable access to novel MXene compositions and surface chemistries.

Main Methods:

• Computational screening of MXene and precursor compositions using first-principles calculations.
• Development of a thermodynamic model based on the CALPHAD approach.
• Experimental validation of predicted optimal synthesis conditions (temperature and pressure).

Main Results:

• Identification of MXene candidates with high phase stability and low etching energy for dry selective extraction (DSE).
• Thermodynamic assessment of the DSE reaction for Ti3C2I2, predicting optimal synthesis parameters.
• Experimental verification of the predicted fluorine-free dry synthesis conditions.

Conclusions:

• Dry selective extraction (DSE) offers a viable fluorine-free route for MXene synthesis.
• Computational modeling accurately predicts synthesis parameters for uniform surface terminations.
• This method expands the possibilities for scalable MXene production with tailored properties.