Natural Polyphenol‐Mediated Multifunctional Separation Materials for Water Remediation: Recent Developments and Future Perspectives

Natural plant polyphenols represent a unique class of supramolecular building blocks, featuring abundant catechol and pyrogallol moieties that enable simultaneous engagement in multiple dynamic covalent and noncovalent interactions—including hydrogen bonding, coordination chemistry, π–π stacking, and hydrophobic association—with chemically diverse substrates. These versatile supramolecular interactions have established polyphenol‐mediated interfacial functionalization as a powerful and emerging platform for constructing advanced separation materials for water remediation. This review systematically examines how the supramolecular chemistry of plant polyphenols underpins the rational design of separation interfaces, and highlights recent progress across three mechanistic categories: adsorptive separation, membrane filtration, and solar distillation. Key strategies for leveraging polyphenol–substrate supramolecular interactions to achieve high separation performance, excellent customizability, and environmental sustainability are discussed. Finally, future perspectives on expanding the supramolecular design space of polyphenol‐based separation materials are proposed to inspire further innovations in high‐performance and eco‐friendly separation technologies. This review provides a comprehensive and timely overview of the critical role of polyphenol‐mediated supramolecular interface engineering in separation materials. It is anticipated that this review will provide new opportunities to bridge natural biomass resources with advanced separation materials design for addressing increasingly urgent challenges in water purification.