3D Knitted Interfacial Solar Steam Generator for High‐Efficiency and Long‐Term Seawater Desalination

Interfacial solar steam generators (ISSGs) can concentrate photothermal conversion and water evaporation at the liquid–vapor interface, thereby achieving highly efficient water evaporation. Nevertheless, conventional ISSGs are plagued by complex fabrication, severe salt accumulation, and lack of autonomous floating. Herein, a special‐shaped knitted structural interfacial solar steam generator (SKSSG) was fabricated via two‐dimensional weaving and 3D knitting technologies, integrating high evaporation performance, rapid water delivery, excellent salt tolerance, and self‐floating capability. The spacer yarn (SY) with a directional vertical structure enables efficient water transport, while the bottom surface woven from polyethylene filaments endows the device with self‐floating ability. The water transport rate of the edge yarn (EY) is lower than that of SY, resulting in salt enrichment in EY and the formation of a concentration gradient with the evaporation interface, thereby triggering the Marangoni effect to achieve rapid salt migration and exchange. Under 1 kW m ⁻² illumination, SKSSG achieves an evaporation flux of 1.91 kg m ⁻² h ⁻¹ (with an efficiency of 96.2%), and no surface salt crystallization is observed after 6 h of continuous operation in a 25 wt% NaCl solution. Additionally, techno‐economic analysis confirms its promising commercial potential.