Autonomous and Continuous Atmospheric Water Harvesting Using Modified Wood

To overcome global water scarcity, it is necessary to develop technologies to provide efficient access to freshwater without geographical limitations. Sorption-based atmospheric water harvesting (SAWH), a promising solution, presents limitations of low water uptake capacity of adsorbents, high energy consumption, and limited cycle stability. In this paper, a high-performance SAWH composite material prepared by co-incorporating a poly(N-isopropylacrylamide)/polyacrylic acid (PNipam/PAA) network with lithium chloride (LiCl) into delignified wood (DW) is presented. In which the rigid, hydroxyl-rich wood skeleton with graded channels serves as a multifunctional host to promote water transport and storage, while inhibiting thermal-desorption-induced structural deterioration of PNipam, thereby overcoming the cycling stability issue of PNipam/PAA-LiCl in SAWH applications. Compared to other biomass adsorbents, the PNADW-LiCl exhibits high water absorption (0.998 g g⁻ ¹) and rapid sorption kinetics at 70% RH. Meanwhile, the material enables rapid and efficient water desorption at 80 °C and maintains stable performance over 10 consecutive absorption-desorption cycles. An automated, continuous, solar-powered AWH device is further developed. A 24-h real-world outdoor (Harbin, China) test shows a water production of 2.631 L kg⁻ ¹·day⁻ ¹, which is much better than the reported method. This work provides valuable insights for designing next-generation sustainable, efficient, and stable renewable atmospheric water harvesting materials and systems.