Macro‐Micro‐Nano Asymmetric Light‐Trapping Architecture Enabling Spatial Decoupling of Evaporation‐Salt Crystallization for Efficient Solar Desalination

Abstract Solar‐driven interfacial evaporation (SSG) systems represent a sustainable technology for addressing global water scarcity, yet achieving high efficiency, salt rejection, and scalability remains challenging. Inspired by the Salvinia plant, this study presents a flexible 3D evaporator photothermal membrane (TPM) with macro‐micro‐nano multiscale asymmetric structures, fabricated using scalable textile processes. TPM integrates MXene‐coated chenille yarns (CY) and woven fabric (WF) into an asymmetric architecture that spatially decouples evaporation and salt crystallization. The hydrophilic CY tufts drive intense localized evaporation and rapid water transport, while the WF, lacking significant photothermal properties and exhibiting weaker hydrophilicity—serves only as a mechanical support, remaining decoupled from the evaporation process. The TPM achieves a high evaporation rate of 4.12 kg m −2 h −1 under 1‐sun with reduced evaporation enthalpy. Salt deposition is effectively localized to CY tufts due to their combined photothermal properties and high hydrophilicity. Moreover, the excellent water transport capability of the CY facilitates capillary‐driven nocturnal salt backflow, dissolving and redistributing accumulated salts during non‐illumination periods, thereby ensuring self‐cleaning and stability. The produced desalinated water meets agricultural standards. Furthermore, the inherent thermal gradient facilitates supplemental thermoelectric power generation. This integrated “Evaporation‐Irrigation‐Electricity” system provides a sustainable path for co‐generating water and energy.