Integrated Nanofluidic Covalent Organic Framework Fibers for Sustainable Wastewater Valorization

ABSTRACT Addressing the global water–energy–human health nexus urgently requires innovative technologies that convert wastewater from an environmental burden into a valuable resource using renewable energy. Here, we present a novel nanofluidic covalent organic framework (COF) fiber system that seamlessly integrates three key functions into a single, scalable architecture, including capture of solar–osmotic coupled energy, targeted metal ion recovery, and on‐site contaminant sensing. The COF fiber exhibits a multiscale porous structure that enables the exceptional kinetic and selective control over ionic transport. Owing to this advanced structural feature, the COF fiber system simultaneously functions as (i) an energy converter that delivers a maximum output power density of 249.4 W/m 2 by harvesting solar–osmotic coupled energy from a 500‐fold NaCl concentration gradient under light illumination; (ii) a fluidic battery enabling self‐powered electrochemical reduction and recovery of metal ions in simulated wastewater, and (iii) a sensor capable of detecting trace levels of Cu 2+ in wastewater, with a detection limit (LOD) as low as 5 n m . The work provides a viable strategy for addressing the intertwined challenges at the water–energy–human health nexus.