Modified MAX Phase Synthesis for Environmentally Stable and Highly Conductive Ti₃C₂ MXene

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Two-dimensional (2D) titanium carbide (Ti3C2) MXene is a promising material for various applications.
• Limited research and commercial use are hindered by the rapid oxidation and degradation of MXene aqueous suspensions.

Purpose of the Study:

• To enhance the stability and properties of Ti3C2 MXene.
• To overcome the limitations posed by oxidation and degradation of MXene suspensions.

Main Methods:

• Synthesized Ti3AlC2 MAX phase precursor with excess aluminum, termed Al-Ti3AlC2.
• Produced Al-Ti3C2 MXene nanosheets from the modified precursor.
• Evaluated oxidation resistance, electronic conductivity, and shelf life of Al-Ti3C2 suspensions and films.

Main Results:

• Al-Ti3AlC2 precursor yielded MXene nanosheets (Al-Ti3C2) with improved crystallinity and carbon stoichiometry.
• Al-Ti3C2 exhibited significantly increased resistance to oxidation and higher electronic conductivity (up to 20,000 S/cm).
• Aqueous suspensions of Al-Ti3C2 showed an extended shelf life of over ten months, compared to 1-2 weeks for conventional Ti3C2.
• Films made from stored Al-Ti3C2 suspensions maintained high electrical conductivity and showed negligible oxidation.
• Oxidation of Al-Ti3C2 initiated at 100-150 °C higher temperatures than conventional Ti3C2.

Conclusions:

• The modified synthesis approach significantly improves the quality, stability, and conductivity of Ti3C2 MXene.
• Enhanced Al-Ti3C2 demonstrates remarkable shelf-life stability in aqueous suspensions and improved thermal oxidation resistance.
• These findings facilitate the wider adoption and commercialization of MXene materials.