Large-scale 3D printed fouling-resistant self-floating evaporator
Yiru Pu, Wenzhu Lin, Xiaoxue Yao, Qili Xu, Wai Kin Lo, Yuyi Liu, Jiawei Sun, Yijun Zeng, Songnan Bai, Miaomiao Cui, Stevin S. Pramana, Tong Li, Zuankai Wang, Steven Wang
Abstract
Solar-driven interfacial desalination is an emerging approach to address global freshwater crisis while minimizing carbon emissions. A key challenge in interfacial desalination technology is maintaining long-term high efficiency with fouling-resistance and energy-saving. Here, we develop a 3D-printed concave-shaped solar evaporator and a floating freshwater collection setup, that achieve nearly 100% photothermal evaporation efficiency with a rate of 2.23 $${{{\rm{kg}}}}{{{{\rm{m}}}}}^{-2}{{{{\rm{h}}}}}^{-1}$$ and freshwater collection rate of 1.23 $${{{\rm{kg}}}}{{{{\rm{m}}}}}^{-2}{{{{\rm{h}}}}}^{-1}$$ under one sun illumination. This 3D concave-shaped solar evaporator design, achieved through 3D printing and double-sided surface modification, allows interfacial desalination process to occur at the bottom surface of the evaporator with superior heat transfer, ultra-effective salt-resistance and enlarged water-air interfacial area. The evaporation stability, extending well beyond traditional limitations of days or months, is realized by a decoupling design and the low-cost renewal of water-intake layer. This design allows vapor to escape downward without causing fouling problem within the top solar absorber. Furthermore, a self-floating freshwater collection setup facilitates thermal exchange with low-temperature seawater for sustainable application. Our large-scale integrated 3D printed evaporator-collector strategy demonstrates potential for portable solar-driven interfacial desalination and freshwater collection. This solar-driven interfacial desalination research integrates 3D printed modules modifications, decoupling design, anticorrosion treatment for high desalination efficiency and long-term stability. This self-floating setup utilizes natural cooling seawater to conduct thermal convection for downward freshwater collection.