Electrostatically Self-Assembled Coaxial-Roll Evaporator: Achieving Ultra-High Efficiency and Durability for Sustainable Seawater Desalination and Irrigation

Solar-driven interfacial evaporation (SDIE) technology demonstrates significant potential in seawater desalination, yet its evaporation efficiency and durability remain constrained by bottlenecks such as insufficient solar-to-thermal conversion efficiency, impeded water transport, and salt contamination accumulation. This study proposes a three-step strategy of “electrostatic self-assembly photoreduction-winding” to construct a coaxial rolled evaporator (CRE) comprising reduced rGO/Cu 2 O–OHNMs@MF. Based on nanomacro-scale codesign, this structure employs a p–n heterojunction array to drive photogenerated carrier separation and localized heat release, thereby reducing water vaporization enthalpy. Radial spiral slits form a gradient capillary network enabling rapid water supply and reverse diffusion of salt ions. The outer rGO pleated photothermal layer enhances solar energy capture while inhibiting salt crystallization. Under 1 kW m –2 irradiation, the CRE system achieves an evaporation rate of 2.58 kg m –2 h –1 with 97.19% efficiency, maintaining structural integrity under extreme conditions including pH = 1–14, 90 °C temperatures, ultrasonic agitation, and mechanical compression. After 20 consecutive cycles of operation in real seawater, the performance retention rate reaches 94.87%. The desalinated water meets WHO drinking water standards and supports normal wheat growth. Overall, this study provides innovative insights and practical solutions for highly efficient, salt-tolerant, antimicrobial, and scalable solar seawater desalination as well as agricultural irrigation technology.