To tackle global water pollution and shortage, solar-driven interfacial water evaporation has been demonstrated as a promising strategy for clean water generation. However, most of the previous reported interfacial evaporation...

Solar‐driven vapor generation is a promising method to mitigate freshwater shortage and water contamination. However, most of the current highly efficient solar evaporators suffer from low robustness, tedious preparation procedures, and high cost. In this study, an easy‐to‐manufacture, low‐cost, and high‐reliability solar‐driven evaporator is designed using a black cotton towel with a hollow conical shape. The reactive dye molecules diffuse into the cotton and form strong covalent bonds with the fiber after dyeing, which firmly fixes light‐absorbing materials on the substrate. The looped pile structure of towels and hierarchical structure of yarns enable the evaporator enlarged surface area. The hollow conical shape of the cotton towel can effectively suppress the heat loss to the environment without compromising light absorption. The 3D vapor generator exhibits an evaporation rate of 1.40 and 1.27 kg m−2 h−1 for pure water and saline water, respectively. Meanwhile, this towel‐based solar‐driven evaporator exhibits a promising antifouling property as well as superior reusability and provides a reliable pathway in dealing with realistic waters, such as seawater and dyeing sewage. Therefore, the low‐cost, solar‐driven water evaporation system offers a complementary approach for high‐efficiency vapor generation and water purification in practical application.

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An efficient, low-cost, and easy-to-fabricate solar steam generator is needed to mitigate clean water scarcity in less-resourced areas. A balanced water supply demand (WSD) to the photothermal conversion layer (PCL) plays a key role in improved heat management and evaporation rate. Here, we designed a solar steam generator of integrated multi-layered fabric (IMLF) in which WSD can be tuned by varying the degree of polypyrrole (PPy) coating. The hydrophilic viscose yarn deposited with PPy is exploited as the surface, and the hydrophobic hollow polyester is used as the inner warp and weft yarn. Under 1 solar light intensity, IMLF attains an evaporation rate of 1.15 kg m–2 h–1 and a corresponding evaporation efficiency of ∼77.9%. Within 16 cycle tests, the evaporation rate of the IMLF fluctuates in the range of ∼1.00 to 1.16 kg m–2 h–1, indicating good cycle stability. Furthermore, the condensate obtained from actual seawater satisfies EPA and WHO drinking water standards. Our findings demonstrate that the IMLF is capable of effectively treating seawater and dyeing effluent.

In article number 1900004, Bi Xu and co‐workers design an easy‐to‐manufacture, low‐cost, and highly reliable solar‐driven evaporator for water purification using a black cotton towel with a hollow conical shape. The reactive dye molecules diffuse into the cotton and form strong covalent bonds with the fiber after dyeing, which firmly fixes light‐absorbing materials on the substrate.