Atomically Thin Sieves: Two‐Dimensional Materials for Membrane Separation

ABSTRACT Membrane separation technology is a promising strategy due to its high efficiency and low energy consumption, yet conventional 3D porous membranes suffer from an inherent selectivity‐permeability trade‐off. Defect‐free 2D materials have proven intrinsically impermeable to almost all gases and ions, making them perfect barrier matrices. Creating nanopores with precisely controlled shape and size in these crystals enables not only fit‐for‐purpose sieving of molecules and ions, but also high flux mass transport owing to their atomic‐scale thickness. Here, we discuss the transport mechanisms through 2D membranes along with well‐established fabrication strategies, followed by an examination of recent experimental and theoretical advances. Finally, we explore the potential applications of atomically thin membranes and provide a perspective on the prevailing challenges and future prospects.