On-demand linkage cleavage in two-dimensional conjugated metal-organic frameworks for closed-loop recyclable...

Area of Science:

• Materials Science
• Sustainable Chemistry
• Nanotechnology

Background:

• Electronic waste is a growing global concern, necessitating sustainable management strategies.
• Closed-loop recycling of complex electronic materials, like metal-organic frameworks, is crucial but challenging.
• Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) offer multifunctional properties for advanced electronics.

Purpose of the Study:

• To develop and demonstrate a closed-loop recycling strategy for 2D c-MOFs.
• To establish a sustainable material lifecycle for 2D c-MOFs through on-demand degradation and regeneration.
• To assess the environmental benefits and practical applications of recyclable 2D c-MOFs.

Main Methods:

• Mechanochemistry-induced on-demand degradation using ultrasonic cavitation in alkaline solutions.
• Selective cleavage of metal-ligand bonds in HHTP-based 2D c-MOFs.
• Recovery and reuse of HHTP monomers for regenerating 2D c-MOFs.

Main Results:

• Achieved rapid material degradation (92.4% in 30 min) and high monomer recovery (96.3% purity and yield).
• Established a complete circular material lifecycle for 2D c-MOFs.
• Demonstrated significant reductions in energy consumption (85.6%) and CO2 emissions (82.5%) compared to direct synthesis.
• Validated the utility of recyclable 2D c-MOFs in hydrogen gas sensors, supercapacitors, and printed electronics.

Conclusions:

• The mechanochemistry-induced closed-loop recycling strategy is effective for 2D c-MOFs, enabling a circular material economy.
• This approach significantly lowers the environmental footprint of electronic materials, promoting sustainability in the electronics industry.
• Recyclable 2D c-MOFs show promise for advancing circular electronics and sustainable technological development.