Acid Resistant and Highly Silver Selective Membranes Based on Charged Nanoporous 2D-Materials

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Growing volumes of waste electrical and electronic equipment (WEEE) pose environmental challenges.
• Current recycling rates for WEEE are low, leading to the loss of valuable and critical metals.
• Sustainable and energy-efficient separation techniques are needed to recover metals from WEEE.

Purpose of the Study:

• To introduce a novel nanofiltration membrane for selective ion separation.
• To assess its applicability in recovering metals from WEEE leachates, particularly silver (Ag).
• To evaluate the membrane's stability in acidic media for hydrometallurgical processes.

Main Methods:

• Fabrication of a nanofiltration membrane using charged, fully exfoliated, nanoporous 2D nanosheets.
• Testing the membrane's selectivity for silver (Ag) against other metals in simulated WEEE leachates.
• Investigating ion transport mechanisms (intra- and inter-lamellar) within the membrane.
• Assessing membrane stability in acidic conditions.

Main Results:

• The novel 2D membrane demonstrated exceptional selectivity for silver (Ag) over other metals.
• The membrane exhibited remarkable stability in acidic media, suitable for hydrometallurgical applications.
• Two distinct ion transport mechanisms were identified, enabling rapid separation within 2 minutes.
• The technology is highly relevant for silver recovery in solar panel recycling.

Conclusions:

• Charged 2D nanosheet membranes offer a sustainable and energy-efficient solution for metal recovery from WEEE.
• The developed membrane technology shows significant promise for enhancing recycling processes, particularly for silver.
• The rapid and selective separation capabilities highlight the potential of advanced membrane technologies in circular economy initiatives.