Fluoride-Free Synthesis of Two-Dimensional Titanium Carbide (MXene) Using A Binary Aqueous System

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Two-dimensional (2D) titanium carbide (Ti3C2) is a key MXene material with significant application potential.
• Current synthesis methods often rely on hazardous fluoride-based etchants, hindering practical use.
• Developing safe and efficient synthesis routes is crucial for MXene advancement.

Purpose of the Study:

• To develop an efficient, fluoride-free synthesis method for 2D Ti3C2 MXenes.
• To characterize the properties of the synthesized Ti3C2 flakes.
• To evaluate the performance of Ti3C2-based supercapacitors.

Main Methods:

• Anodic corrosion of titanium aluminium carbide (Ti3AlC2) in a binary aqueous electrolyte.
• In situ intercalation of ammonium hydroxide after aluminium dissolution.
• Extraction of Ti3C2 Tx flakes (T=O, OH).
• Fabrication and testing of all-solid-state supercapacitors.

Main Results:

• Achieved a high yield (>90%) of Ti3C2 Tx flakes, including mono- and bilayers, with sizes up to 18.6 μm.
• Synthesized Ti3C2 flakes exhibit superior performance in all-solid-state supercapacitors compared to fluoride-etched MXenes.
• Demonstrated high areal capacitance (220 mF/cm²) and volumetric capacitance (439 F/cm³).

Conclusions:

• The fluoride-free anodic corrosion method offers a safe and scalable route for Ti3C2 MXene synthesis.
• This approach overcomes limitations of traditional fluoride-based methods.
• The developed Ti3C2 materials show promise for high-performance energy storage devices.