Solar generation technology is considered to be one of the most promising seawater desalination methods. To achieve a high and stable water production rate, the absorber structure and salt deposition are two key problems to be solved. As an effective salt-rejecting structure, a Janus structure can promote steam generation efficiency by reducing heat loss compared with traditional superhydrophilic structures. Here, we designed a Janus biomass carbon/sponge (JBCS) evaporator composed of carbonized original leaf particles and commercial melamine sponge seamlessly integrated with each other by a simple “soak-dip” method. The upper hydrophobic carbon sponge provides excellent salt-rejection and good heat-localization, while the seamless hydrophilic melamine sponge underneath ensures a continuous water supply. The synergistic advantages of the Janus structure allow the evaporator to maintain a stable photothermal conversion efficiency of 86.5% without salt deposition in 3.5 wt% NaCl solution under 1 sun. Therefore, the sustainable JBCS can be used as a promising option to obtain clean fresh water resources to meet the needs of water-scarce areas.

中文翻译：

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设计具有拒盐和易于漂浮的Janus生物质碳/海绵蒸发器，以实现可持续的太阳能驱动淡化

太阳能发电技术被认为是最有前途的海水淡化方法之一。为了获得高且稳定的产水率，吸收器结构和盐分沉积是需要解决的两个关键问题。作为一种有效的排盐结构，与传统的超亲水结构相比，Janus结构可以通过减少热量损失来提高蒸汽产生效率。在这里，我们设计了Janus生物质碳/海绵（JBCS）蒸发器，该蒸发器由碳化的原始叶片颗粒和商用三聚氰胺海绵组成，它们通过简单的“浸入-浸入”方法彼此无缝集成。上层疏水性碳海绵提供了出色的防盐性和良好的热定位性，而下方的无缝亲水性三聚氰胺海绵确保了连续供水。Janus结构的协同优势使蒸发器能够在1个阳光下在3.5 wt％的NaCl溶液中保持稳定的光热转化效率（86.5％）而不会发生盐沉积。因此，可持续的JBCS可以作为获得清洁淡水资源以满足缺水地区需求的有前途的选择。