Defect-Selective Etching Engineering of Reduced Graphene Oxide Membranes

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Two-dimensional laminar membranes face a permeability-selectivity trade-off, limiting their use in water treatment.
• Reduced graphene oxide (rGO) membranes show potential but require improved performance.

Purpose of the Study:

• To overcome the permeability-selectivity trade-off in rGO membranes.
• To engineer dual transport pathways for enhanced water treatment.
• To develop high-performance, energy-efficient membranes for sustainable water purification.

Main Methods:

• Nanoscale "defect-excavation" strategy using mild KOH etching to create vertical nanopores.
• Ionic-liquid intercalation for thermodynamic stabilization and expanded interlayer spacing.
• Molecular dynamics simulations to elucidate transport mechanisms.

Main Results:

• Optimized KOH-IL-rGO membrane achieved ultrahigh water permeance (455 L m⁻² h⁻¹ bar⁻¹).
• Achieved high methylene blue rejection (99.68%).
• Simulations confirmed dual pathways enhance permeance and selectivity.

Conclusions:

• Synergistic integration of nanoetching and ionic-liquid intercalation creates effective dual nanoscale transport networks.
• This approach provides a rational design for high-performance, energy-efficient membranes.
• Demonstrates a viable strategy for sustainable water purification and recovery.