Self‐Assembled Conjugated Hollow Fibers for Spongy Monoliths Toward Solar‐Driven Desalination and Hydrovoltaic Electricity Generation

ABSTRACT This study presents a molecular design strategy for a self‐assembled conjugated hollow‐fiber monolith that enables simultaneous solar‐driven desalination and hydrovoltaic electricity generation. In this bottom‐up approach, aromatic monomers undergo metal‐free condensation to form cross‐linked hollow fibers that spontaneously entangle into a spongy monolith in a single step without templates. A gradient coating of polypyrrole subsequently yields a hierarchical aerogel that facilitates efficient light absorption, directional water transport, and interfacial solar evaporation through outer channels while suppressing bulk infiltration through a hydrophobic inner core. The developed system exhibits a high evaporation rate with strong salt resistance. The desalinated seawater produced under outdoor conditions meets World Health Organization drinking‐water standards and supports rice seed germination under natural sunlight, confirming its potential for potable water production and agricultural irrigation. Solar‐induced ion migration within the hollow channels generates hydrovoltaic outputs tunable by electrolyte salinity and device configuration, thereby enabling concurrent freshwater production and energy harvesting. Overall, the proposed system constitutes an integrated single‐material platform that addresses the global water–energy nexus through sustainable, low‐cost solar purification and electricity generation.