Mono/divalent ions separation is an extremely crucial yet difficult task. Two-dimensional (2D) graphene oxide (GO) membranes with exquisite interlayer nanochannels are promising to discriminate mono/divalent ions, but they suffer from serious swelling issue. Inspired by biological metal cation immobilization paradigm, we propose a universal chelation-based metal cation stabilization strategy of GO membranes. The chelation of polydentate ligand with metal cation generates thermodynamically stable coordination complexes to sustain GO interlayer via multiple binding forces. By synergism of firmly immobilized metal cations controlling 2D nanochannels against swelling to ensure divalent ions retention, and rationally incorporated polydentate ligands decorating 2D nanochannels with hydrophilic groups to facilitate monovalent ions permeation, the as-fabricated GO/ligand-M²⁺ membranes afforded superior sieving performance of monovalent ions permeance of ∼0.78 mol m⁻² h⁻¹ and mono/divalent ions selectivity of ∼23.5. This work provides a general design concept for the stabilization of 2D laminar membranes towards efficient sieving of mono/divalent ions.

一价/二价离子分离是一项极为关键但又十分艰巨的任务。具有精细层间纳米通道的二维 (2D) 氧化石墨烯 (GO) 膜有望区分一价/二价离子，但它们存在严重的溶胀问题。受生物金属阳离子固定范式的启发，我们提出了一种通用的基于螯合的 GO 膜金属阳离子稳定策略。多齿配体与金属阳离子的螯合产生热力学稳定的配位络合物以维持 GO 夹层通过多重约束力。通过牢固固定的金属阳离子的协同作用，控制二维纳米通道以防止膨胀以确保二价离子保留，并合理掺入用亲水基团装饰二维纳米通道以促进单价离子渗透的多齿配体，制备的 GO/配体-M ²⁺膜提供了优异的筛分性能表现出~0.78 mol m ^-2  h ^-1的单价离子渗透性和~23.5的单价/二价离子选择性。这项工作为稳定二维层状膜以实现单价/二价离子的有效筛分提供了一般设计概念。