Salt‐Templated Crystallization Yields Oriented Interconnected Macroporous Polymer Gels for Ultrafast and High‐Capacity Atmospheric Water Harvesting

ABSTRACT Sorption‐based atmospheric water harvesting (SAWH) is a promising strategy for freshwater production. While salt‐based composites are widely employed as SAWH sorbents, they are often constrained by limited water yield from low sorption capacity and slow sorption/desorption kinetics due to diffusion barriers. Here, a new strategy is proposed to enhance moisture transport and storage space by fabricating oriented interconnected macroporous polymer gels via salt‐templated crystallization‐induced confined polymerization. Benefiting from this optimized interconnected hierarchical structure and the synergistic effect between PAMPS and LiCl, the salt‐templated crystallization gel (STC/TiN‐gel@LiCl) exhibits a record‐breaking moisture uptake of 7.19 g g − 1 , ultrafast sorption kinetics of 1.96 g g − 1 h − 1 , and rapid desorption rate of 96.8% per hour under 1.0 sun illumination. After 20 cycles under high‐humidity conditions (25°C, 90% RH), the gel retains over 90.4% of its initial water uptake capacity without leakage, confirming its long‐term durability. Moreover, it delivers an outstanding water production rate of 3.29 kg kg − 1 day − 1 even under low‐temperature and moderate humidity conditions (14.5°C, 55.6% RH). This work pioneers an oriented interconnected macroporous architecture engineering strategy to concurrently unlock rapid transport and high‐capacity storage in hygroscopic gels, establishing a new paradigm for atmospheric water harvesting.