Heterocyclic covalent organic framework membranes for water purification

growth, covalent organic nanosheet (CON) stacking, and matrix blending. Furthermore, we highlight the multifunctional utility of HC-COFMs across five key application domains: molecular separation, ion sieving, membrane catalysis, solar-driven water purification, and emerging applications including critical metal recovery and remediation of emerging organic microcontaminants. All these functionalities are underpinned by the exceptional anti-fouling properties and chemical stability intrinsic to heterocyclic COF architectures. Finally, we outline current bottlenecks and future research directions, offering a strategic roadmap to guide the rational design of next-generation HC-COFMs for sustainable, cross-disciplinary water-energy-environment applications.