Publication
Atomically thin graphene membranes with sub-1-nm pores show promise for ion/molecular separation, osmotic energy generation, and energy storage. Narrowing the pore size distribution and controlling the surface charge are essential to achieve these applications. However, nanoporous graphene membranes fabricated via conventional methods possess a broad pore size distribution and inadequately regulated surface charge, limiting their applications. Herein, we present a molecular anchoring approach for scalable synthesis of nanoporous graphene membranes via a bottom-up technique, aiming to narrow the pore size distribution without reducing the pore density while simultaneously adjusting the charge properties of nanopores. By selecting suitable anchoring molecules, the custom-tailored pore size distribution and chemical functionality of nanoporous graphene membranes can be achieved. Leveraging the steric restriction effect, anchoring monomers selectively traverse larger nanopores to form ion-selective plugs, effectively repairing these nanopores. The centimeter-scale nanoporous graphene membrane with an ion-selective plug achieves high separation selectivity (K + /Na + =20, K + /Mg 2+ =330). Theoretical simulations indicate that a smaller pore size, narrow pore size distribution, and positive charge result in a larger energy barrier difference, leading to ultrahigh metal ion selectivity. Furthermore, in treating lithium battery leaching solutions, Li + /divalent ions selectivity exceeds 900. These findings provide a way for designing graphene-based membranes. Membranes with angstrom-level ion selectivity and ultrahigh ion permeability are desirable for high-efficiency separation applications such as ion separation, gas separation, organic solvent nanofiltration, and electrochemical energy conversion and storage 1-5. The latest advancements in membranes with pore sizes less than 1 nm have significantly enhanced ion sieving performance, sparking considerable research interest. Among these, commercially produced chemical vapor deposition (CVD) graphene, made via the roll-to-roll technique 6-8 , has positioned atomically thin graphene membranes with angstrom-sized pores as leading candidates for ion separation owing to its atomic-scale thickness 9 , enhanced mechanical integrity 10,11 , and low flow resistance 12 to potentially transform the domain of traditional membrane-based separation technologies. Theoretical and experimental studies have demonstrated that nanoporous atomically