Bioinspired topological design of super hygroscopic complex for cost-effective atmospheric water harvesting

As a promising technology for water scarcity alleviation, Atmospheric Water Harvesting (AWH) appeals for adsorbents with high performance, low cost, low environmental impact, and low energy consumption for practical application. Herein, a super hygroscopic complex based on natural Loofah grafted Calcium Alginate sorbent with Ink (ILCA) with comprehensive performance assessment is developed for the first time. It is found that the sorbent can adsorb 0.5–1.2 g g−1 water at 30%−60% RH, then desorb it rapidly under 1 sun (1.5 kg m−2 h−1)). Moreover, around 2.8 g of water can be collected by 4.96 g ILCA in 5 h (23 °C, RH50%). This work further conducted a techno-economic analysis of ILCA and found that 1 kg water can be harvested with a material cost of only $0.84 (e.g. cheapest option in literature). Such results harbor the potential for sustainable, eco-friendly, and cheap AWH that can be used in underdeveloped regions with high solar energy potential.