As an effective way to obtain freshwater resources, atmospheric water harvesting (AWH) technology has been a wide concern of researchers. Therefore, hydrogels gradually become key materials for atmospheric water harvesters due to their high specific surface area and three-dimensional porous structure. Here, we construct a core–shell hydrogel-based atmospheric water harvesting material consisting of a shell sodium polyacrylate (PAAS) hydrogel with an open pore structure and a core thermosensitive poly N-isopropylacrylamide (PNIPAAm) hydrogel with a large pore size. Theoretically, the mutual synergistic hygroscopic effect between the core layer and the shell layer accelerates the capture, transport, and storage of moisture to achieve continuous and high-capacity moisture adsorption. Simultaneously, the integration of polydopamine (PDA) with the hydrogel realizes solar-driven photothermal evaporation. Therefore, the prepared core–shell hydrogel material possesses great advantages in water adsorption capacity and water desorption capacity with an adsorption of 2.76 g g^–1 (90% RH) and a desorption of 1.42 kg m^–2 h^–1. Additionally, the core–shell structure hydrogel collects 1.31 g g^–1 day^–1 of fresh water in outdoor experiments, which verifies that this core–shell hydrogel with integrated photothermal properties can capture moisture in a wide range of humidity without any external energy consumption, can further sustainably obtain fresh water in remote water-shortage areas.

中文翻译：

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具有核壳结构的可持续分层多孔 PAAS-PNIPAAm 水凝胶专为高效大气水收集而设计

作为获取淡水资源的有效途径，大气集水（AWH）技术一直受到研究人员的广泛关注。因此，水凝胶以其高比表面积和三维多孔结构逐渐成为大气水收集器的关键材料。在这里，我们构建了一种基于核壳水凝胶的大气集水材料，该材料由具有开孔结构的壳聚丙烯酸钠 (PAAS) 水凝胶和核热敏聚N- 具有大孔径的异丙基丙烯酰胺 (PNIPAAm) 水凝胶。从理论上讲，芯层和壳层之间的相互协同吸湿作用加速了水分的捕获、运输和储存，从而实现持续、高容量的水分吸附。同时，聚多巴胺（PDA）与水凝胶的结合实现了太阳能驱动的光热蒸发。因此，所制备的核壳型水凝胶材料在吸水量和解吸量方面具有很大的优势，吸附量为2.76 gg ^–1 (90% RH)，解吸量为1.42 kg m ^–2 h ^–1。此外，核壳结构水凝胶收集 1.31 gg ^–1 day ^–1户外淡水实验验证了这种具有集成光热特性的核壳水凝胶可以在不消耗任何外部能源的情况下捕获大范围湿度范围内的水分，进一步为偏远缺水地区可持续获取淡水。