Advances in Hygroscopic Polymer Gels toward Efficient Atmospheric Moisture Capture and Management

Atmospheric humidity, as a widely distributed environmental resource, holds great potential to create significant value for human society via efficient regulation and utilization. Hygroscopic polymer gels (HPGs) have emerged as a highly promising material platform for atmospheric moisture capture, owing to their highly tunable structures, unique swelling behaviors, and versatile functionality. In this review, recent advances in HPGs, including the hygroscopic mechanisms and state-of-the-art construction strategies, are systematically summarized. Furthermore, cutting-edge applications of HPGs, including atmospheric water harvesting, electricity production, thermal management, fuel production, advanced greenhouses, dehumidification, and HPGs-based electrolytes, are thoroughly discussed. The review places particular emphasis on the urgent need to intensify the design and development of HPGs specifically tailored for sustainable applications in challenging low-humidity arid regions. Finally, the current challenges are summarized, and future research directions for next-generation HPGs in atmospheric moisture management are outlined, aiming to fully harness the potential of atmospheric humidity as an abundant and renewable resource.