Synergistic Structural Alignment and Interfacial Switching Enable Fast and Low–Energy Water Release in Solar–Driven Atmospheric Water Harvesting

Abstract Atmospheric water harvesting (AWH) addresses freshwater scarcity, but most sorbents struggle with trade–offs between high moisture uptake, rapid desorption and low–energy regeneration. Herein, a multiscale composite is developed, integrating vertically aligned delignified wood (DW) microchannels, microporous MOF‐801 domains, and a thermoresponsive poly (N‐isopropylacrylamide)–MXene (PNIPAM–MXene) interface via interfacial synergy. The PNIPAM–MXene interface works dually, MXene’s high photothermal efficiency raises local temperature under solar light to trigger PNIPAM’s entropy–driven phase transition. This synergy switches wettability from hydrophilic to hydrophobic for water release, breaks water–matrix hydrogen bonds, and reduces desorption activation energy by ~19%. Under humid conditions, the composite has a water uptake of 0.82 g·g ⁻¹ , and releases ~93.9% of absorbed water under simulated solar irradiation. Molecular simulations confirm PNIPAM’s entropy–driven transition disrupts interfacial hydrogen bonds, promoting confined water expulsion. This strategy enables low–energy solar–driven AWH, with scalable potential for off–grid water production in arid regions, offering insights for designing multifunctional sorbents bridging high capacity and easy regeneration.