AlCl₄^--Intercalation Driven Molten Salt Electroetching with Closed-Loop Al Recovery

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Conventional MXene synthesis methods often employ hazardous etchants, posing environmental and safety concerns.
• There is a critical need for sustainable and eco-friendly alternatives in MXene production.

Purpose of the Study:

• To develop a sustainable molten salt electroetching strategy for MXene fabrication.
• To investigate the selective extraction of aluminum from V2AlC MAX phase using an electrochemical approach.

Main Methods:

• Utilized a LiCl-KCl-AlCl3 molten salt electrolyte for electroetching.
• Employed cyclic voltammetry and chronoamperometry to study the electrochemical process.
• Optimized the applied potential to control aluminum dissolution and preserve MXene layers.

Main Results:

• Achieved efficient aluminum dissolution (30% over 800 cycles) at a critical potential of 2.2 V.
• Demonstrated a closed-loop, self-balanced system with simultaneous aluminum deposition at the cathode.
• Identified AlCl4- intercalation as a key factor enhancing etching kinetics.

Conclusions:

• The molten salt electroetching strategy offers a sustainable and efficient pathway for MXene fabrication.
• Optimized electrochemical parameters are crucial for controlled etching and preventing overetching.
• This method presents a promising eco-friendly alternative to conventional hazardous etchants for MXene synthesis.