GO membranes with well-defined sub-nanometer channels are optimal for desalination and wastewater purification. However

the inherent instability of the interlayer structure and the severe trade-off between selectivity and permeability pose a significant challenge for GO membranes to be effectively applied to nanofiltration. Herein

we synthesized a series of PSSNa-GO-EDA/Al

2

O

3

membranes by embedding poly(sodium 4-styrenesulfonate) (PSSNa) into ethylenediamine-crosslinked GO interlayers. The resultant membranes exhibited greater interlayer structures

in which new hydrophilic confined nanostructures were constructed. Effective nanofiltration performance was achieved through electrostatic-induced ion-confined partitioning. The PSSNa-GO-EDA-1/Al

2

O

3

(PGE-1) membrane showed high rejection rates of 86.0% for Na

2

SO

4

and 53.8% for NaCl while maintaining competitive pure water permeance of 10.85 L·m

-2

·h

-1

·bar

-1

(1 bar = 0.1 MPa)

which is 12.1 times higher than that of the pristine GO membrane. More importantly

after immersion in pure water for 680 h

this membrane retained commendable separation performance. Overall

our work provides an effective strategy to finely fabricate confined nanostructures in lamellar GO-based nanofiltration membranes featuring excellent separation performance.