Confinement-Amplified Tritiated Water Clean-Up in Functionalized Graphene Oxide Nanochannels

Area of Science:

• Materials Science
• Environmental Engineering
• Nanotechnology

Background:

• Tritium separation from aqueous effluents is challenging due to the similar properties of tritiated and light water.
• Existing methods for tritium removal are often energy-intensive or inefficient.
• Graphene oxide (GO) membranes show promise for water purification but require functionalization for specific separations.

Purpose of the Study:

• To develop a highly selective and efficient membrane for tritium removal from aqueous effluents.
• To investigate the synergistic effects of dual functionalization on membrane performance.
• To demonstrate a low-energy, high-throughput platform for tritiated wastewater remediation.

Main Methods:

• Fabrication of a mixed membrane (MIX) by co-assembling carboxyl-functionalized (─COOH) and sulfonic acid-functionalized (─SO₃H) graphene oxide (GO).
• Characterization of the MIX membrane's chemical properties, nanoconfined transport, and separation performance.
• Mechanistic studies to elucidate the roles of ─COOH and ─SO₃H groups in tritium separation and isotope exchange.

Main Results:

• The MIX membrane achieved a single-pass tritium removal efficiency exceeding 21% with a separation factor >1.2.
• Exceptional water permeability (>13 L m^-2 h^-1 bar^-1) was maintained, outperforming single-functionalized membranes.
• ─COOH domains facilitated hydration-assisted enrichment of tritiated water (HTO), while ─SO₃H sites enabled reversible isotope exchange.

Conclusions:

• A cooperative strategy integrating interfacial chemistry and nanoconfinement engineering in 2D membranes was successfully demonstrated.
• The dual-functional GO membrane offers a promising low-energy, high-throughput solution for tritiated wastewater remediation.
• This approach advances the development of advanced materials for environmental cleanup and radioactive waste management.