Biomimetic solar evaporator for continuous clean water production with synergistic organic dye wastewater remediation

Solar-driven water evaporation is recognized as an environment-friendly technology for sustainable clean water generation, serving the needs of both desalination and wastewater purification. However, its practical application is constrained by challenges such as single functionality and significant salt accumulation. Inspired by the transpiration of vascular plant, this work introduces a scalable and cost-effective biomimetic evaporator (PyCOF/ Tri-Layers), consisting of a biomimetic hierarchical fibrous membrane (Tri-Layers) and a composite photothermal layer (PyCOF). Furthermore, the PyCOF composite, featuring an aloe-like flower structure, enhances the light trapping (95.1 %) through multiple scattering, realizing simultaneous desalination and azo dye degradation. Based on the PyCOF/Tri-Layers evaporator, we demonstrate a suspended multi-section hanging evaporation structure sustaining a consistent evaporation rate of approximately 1.41 kg m- 2 h-1 over 15 days without salt accumulation, achieving above 99.3 % removal of dye pollutants within 120 min under one sun irradiation. Moreover, in outdoor experiments, the improved evaporator realizes a daily clean water yield rate of 8.73 kg m- 2 d-1, and the collected water is suitable for supporting crop cultivation within an integrated solar desalination-cultivation system. This work not only provides a one-stone-two-birds approach for generating clean water from polluted seawater, but also presents promising possibilities for offshore self-sustainable agriculture production.