Dual‐Crosslinked Biomass Aerogels Enabling High‐Power and Durable Evaporation Hydrovoltaic Generators

ABSTRACT Cellulose nanofiber (CNF) aerogel‐based water evaporation electricity generators (EEGs) have attracted increasing attention owing to their sustainability and environmental friendliness. However, their practical application is severely hindered by wet structural stability and limited power output. Herein, we report a dual‐crosslinking strategy for constructing a high‐performance CNF‐based aerogel that simultaneously enhances mechanical robustness and hydrovoltaic electricity generation. The aerogel framework is stabilized through synergistic covalent crosslinking between CNFs and carboxymethylated chitosan, combined with metal ionic complexation, resulting in a robust yet highly hydrophilic and water‐resistant macromolecular network. This dual‐crosslinked structure enables efficient hygroscopicity and long‐term stability, facilitating spontaneous and continuous electricity generation via rapid water transport, high ionic conductivity, and strong ion selectivity. As a result, the assembled EEG delivers an output voltage of 0.92 V and a power density of 4.65 µW cm −2 in 3.5% NaCl solution, surpassing most reported EEGs. Moreover, the device demonstrates sustainability through biodegradation and regeneration, while maintaining high power outputs. These results present the strong potential of dual‐crosslinked CNF aerogels for applications in seawater desalination, wastewater treatment, low‐power energy supply, and autonomous water leakage detection, providing a promising platform for self‐powered Internet of Things sensing systems.