Emerging Advances in Atmospheric Water Harvesting with Innovations in Materials and Technologies

Establishing efficient methods for potable water production is essential to mitigate the global water crisis, particularly in geographically and economically constrained arid regions. Atmospheric water harvesting (AWH) has emerged as a sustainable, decentralized, and location-independent solution capable of extracting moisture directly from the air without disturbing the natural hydrological cycle. This review provides a comprehensive overview of AWH technologies, encompassing both condensation- and sorption-based approaches. Traditional fog and dew collectors demonstrate practical viability but suffer from limited efficiency and strong climate dependence, motivating the development of biomimetic architectures and surface-engineered materials. For low-humidity, next-generation sorbent materials, particularly MOFs, hydrogels, hygroscopic salts, and multifunctional composites, have revolutionized AWH performance through tunable pore structures, high water affinity, and rapid sorption–desorption kinetics, enabling efficient water capture and solar-driven release. Thermodynamic and kinetic aspects governing adsorption mechanisms are discussed, emphasizing molecular engineering strategies for optimizing the hydrophilicity, heat transport, and cycling stability. Emerging photothermal and hybrid systems that integrate solar-assisted desorption and passive refrigeration are also evaluated for their improved energy efficiency and scalability. Overall, this review bridges material innovation with device-level implementation, highlighting challenges, including cost, durability, and standardization, and outlining future directions toward economically viable, sustainable, and climate-resilient AWH technologies capable of addressing global freshwater scarcity.