Scalable and efficient solar-driven atmospheric water harvesting enabled by bidirectionally aligned and hierarchically structured nanocomposites

Extracting water from air is a promising route to address the global challenge of water scarcity. Sorption-based atmospheric water harvesting (SAWH) has the capability of capturing water from air anytime and anywhere. However, low water production is a long-standing challenge for realizing efficient SAWH. Here we report a facile strategy to synthesize bidirectionally aligned and hierarchically structured nanocomposite (BHNC) for scalable and efficient SAWH. Benefiting from the synergetic effects of ordered hierarchical structures for accelerating vertically oriented moisture convection and radially oriented intrapore diffusion, the BHNC exhibits ultrahigh water uptake of 6.61 kg_water kg_sorbent^−1 and ultrafast water sorption kinetics, superior to the state-of-the-art sorbents. We further engineer a scalable and efficient solar-driven SAWH prototype by assembling BHNC arrays, demonstrating rapid-cycling and high-yielding water production up to 2,820 ml_water kg_sorbent^−1 day^−1. This work provides new insights to bridge the gap between materials and devices for scalable, energy efficient and all-weather water harvesting from air powered by solar energy.