Integrated Multi-Layered Fabric with Tunable Water Supply to the Photothermal Conversion Layer for an Efficient Solar Water Evaporation

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.