Enhancing Freshwater Production via Customizable and Highly Efficient Solar-Driven Seawater Desalination

Solar-powered water generation is an appealing strategy for cost-effective and energy-sustainable seawater purification/desalination, where rational material selection and device design is crucial. Nevertheless, prevailing carbon-based photothermal materials in such systems still suffer from mediocre steam-to-water efficiency, failing to satisfy an adequate freshwater supply. Herein, we demonstrate a biomimetic corrugated evaporator (CE) affording carbon nanotube (CNT) encapsulated Fe nanocluster-decoration in the pursuit of high-efficiency seawater purification. The thus-customized CE demonstrates a maximum evaporation rate of 4.2 kg m^-2 h^-1 with a refraction angle of 60° and a water-lifting height of 5.5 cm, outperforming most state-of-the-art carbon-based counterparts. By employing a tailored architectural design and optimized condensing volume, the steam-to-water efficiency increases from 65.8 to 88.2% as the volume enlarges from 0.8 to 5.3 L, further harvesting a peak value of 91% under negative pressure. Light intensity simulation and experimental mechanistic investigation disclose the dual property-performance relationships between evaporator microstructure and evaporation rate, as well as between condensing device volume and steam-to-water efficiency. The universality of the theoretical guidance of this work will offer insight into the development of solar-driven evaporator construction toward simultaneous seawater desalination and clean water generation.