Constructing efficient solar-driven interfacial evaporators (SDIEs) derived from biomass or waste stream materials (e.g., cellulose) is still challenging due to their less elaborate porous structure. Herein, we showed waste cotton fabrics could be dissolved and regenerated into aerogels with tunable channels suitable for constructing a double-layered SDIE. The evaporator consists of a polypyrrol-coated top layer featuring vertical channels with larger pores and a hydrophilic bottom layer featuring smaller pores. With such design, the photothermal and pro-evaporative capabilities of the top layer was coupled with the strong capillary effect of the bottom layer to drive effective evaporation. A desirable evaporation rate of 3.20 kg mh, 80.0% solar-to-vapor conversion efficiency under 1 sun irradiation, and a reduced evaporation enthalpy of 962 J g was achieved. The SDIE also exhibits high purification efficiency (exceeding 99%) during long-term operation of seawater desalination and shows great potential in treatment of waste streams of high salinity dyeing effluent. In summary, this work demonstrates a case of upcycling waste cotton fabrics for water desalination.

中文翻译：

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通过废旧棉织物升级改造的双层纤维素界面蒸发器，用于高效太阳能海水淡化


由于其多孔结构不太复杂，构建源自生物质或废物流材料（例如纤维素）的高效太阳能驱动界面蒸发器（SDIE）仍然具有挑战性。在此，我们证明废棉织物可以溶解并再生为具有可调通道的气凝胶，适合构建双层 SDIE。该蒸发器由具有较大孔的垂直通道的聚吡咯涂层顶层和具有较小孔的亲水底层组成。通过这样的设计，顶层的光热和促蒸发能力与底层的强毛细管效应相结合，以驱动有效的蒸发。理想的蒸发速率为 3.20 kg mh，在 1 个太阳照射下，太阳能-蒸汽转化效率为 80.0%，蒸发焓为 962 J g。 SDIE在海水淡化长期运行过程中也表现出较高的净化效率（超过99%），在处理高盐度印染废水中显示出巨大的潜力。总之，这项工作展示了一个将废弃棉织物升级改造用于海水淡化的案例。