Mechanistic and Life-Cycle Framework for Green Nanomaterials in Atmospheric Water Harvesting

Atmospheric water harvesting (AWH) has been recognized as a promising technology to address global freshwater scarcity in a decentralized manner. Nevertheless, conventional AWH sorbents are often associated with high energy consumption, toxic synthesis procedures, and short operational lifetimes. To address such limitations, a comprehensive review paper develops a unified framework to bridge the gap between nanoscale material properties, such as synthesis routes, structural architecture, and adsorption thermodynamics, and macro-scale environmental and economic performance. This review paper rigorously examines emerging nanomaterials such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), mesoporous metal oxides, and graphene oxide derivatives. By highlighting benchmark materials such as MOF-303 and passive solar-regenerated COF-ok, the review paper emphasizes the advantages of bio-assisted "green" synthesis routes. Crucially, this review extends beyond traditional water uptake figures and incorporates comprehensive Techno-Economic Assessments (TEA) and Life-Cycle Assessments (LCA). It examines various real-world influences, such as cumulative energy demand, levelized costs of water, and ton-scale manufacturing viability, to name a few. This report bridges atomic-level mechanics with industrial economics, and by so doing, offers design criteria to guide researchers in crafting a new generation of sustainable AWH infrastructure, with a focus on hierarchical pores, surface chemistry, and photothermal design.