Condition optimization for exfoliation of two dimensional titanium carbide (Ti₃C₂T _x )

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• 2D MXene materials, derived from transition metal carbides, exhibit exceptional properties for energy and environmental applications.
• Titanium carbide (Ti3C2Tx) is a prominent MXene, but its efficient exfoliation from Ti3AlC2 precursor requires optimized chemical etching in hydrofluoric acid (HF).

Purpose of the Study:

• To systematically investigate and determine the optimal conditions for exfoliating Ti3C2Tx MXene from its Ti3AlC2 precursor.
• To evaluate the impact of reaction parameters on the yield, purity, and structural integrity of the resulting Ti3C2Tx.

Main Methods:

• Investigated effects of Ti3AlC2 weight ratio in HF, etching time, temperature, repeated etching, and sonication.
• Analyzed yield, purity, and structure of Ti3C2Tx under varied experimental conditions.

Main Results:

• Optimal exfoliation achieved using 5 wt% Ti3AlC2 etched at 50°C for 36 hours.
• Lower Ti3AlC2 concentrations (0.6-2.5 wt%) led to AlF3 byproduct formation.
• Prolonged etching or higher temperatures caused MXene degradation and AlF3 enrichment.
• Room temperature etching was ineffective; repeated etching denatured the material.
• Controlled sonication during etching significantly reduced time for highly exfoliated MXene.

Conclusions:

• Optimized conditions (5 wt% Ti3AlC2, 50°C, 36h) yield high-quality Ti3C2Tx.
• Controlled sonication presents a promising method for efficient, high-quality MXene production.
• Careful control of etching parameters is vital to prevent byproduct formation and material degradation.