Biopolymer-engineered photothermal platforms for sustainable solar-powered water purification and harvesting

Abstract

Amidst global freshwater scarcity and the unsustainable energy footprint of conventional purification, solar-driven interfacial evaporation (SIE) and atmospheric water harvesting (AWH) have emerged as decentralized, carbon-neutral paradigms, delivering freshwater fluxes that provide an order-of-magnitude enhancement over natural evaporation for sustainable water access. Nevertheless, conventional systems reliant on synthetic polymers or inorganic materials are hampered by considerable socioecological limitations, including ecotoxicological burdens, energy-intensive synthesis, and compromised circularity. This comprehensive review delineates the transformative potential of natural biopolymer-derived structural motifs—elucidating their intrinsic physicochemical properties, diverse material formats, and hierarchical engineering strategies. We further summarize cutting-edge applications of these natural architectures in next-generation SIE and AWH systems, demonstrating how natural biopolymer precision enables unprecedented energy-water nexus efficiency. Through a critical assessment of recent scientific advances and unresolved technological bottlenecks, this review establishes a roadmap for sustainable hydrology innovation. Emphasizing cradle-to-cradle design principles and scalability frontiers, we aim to advance interdisciplinary research that reconciles water security imperatives with planetary boundaries, ultimately stimulating disruptive innovation pathways in bio-inspired water harvesting technologies for global resource equity.