Harnessing Multiple Donnan Effects for Simultaneous Salt‐Resistant Solar Desalination and Dual‐Mode Power Generation

Abstract

ABSTRACT Coupling solar desalination with multi‐mechanism power generation offers a promising dual solution to water and energy crises, yet salt crystallization poses a major obstacle. Here, we present an integrated system featuring as multiple Donnan effects for salt‐resistant solar desalination and dual‐mode power generation. Leveraging the mechanisms of hydrogen bond differentials and Fe 3+ ‐tannic acid crosslinking, a ─SO 3 − ‐functionalized porous sponge evaporator (PSE‐SO 3 − ) was fabricated. Enabled by the Donnan effect of ─SO 3 − groups, the evaporator simultaneously resists salt accumulation and boosts hydrovoltaic power generation, thereby achieving a peak seawater evaporation rate of 4.19 kg m −2 h −1 under one‐sun irradiation while maintaining a salt‐free surface. Simultaneously, PSE2‐SO 3 − generated electricity via the hydrovoltaic effect, delivering outstanding power densities of 5.76/4.34 mW m −2 under one sun/dark conditions. Molecular dynamics simulations and in situ Raman spectroscopy confirmed Cl − interception and elucidated the H + ‐water interaction mechanism for power generation. Furthermore, integrating reverse electrodialysis based on the Donnan effect as an auxiliary strategy enhanced salt resistance of PSE2‐SO 3 − and delivered an osmotic power output of 0.804 W m −2 . Scale‐up of the self‐designed integrated system to an outdoor environment revealed synergistic performance outcomes, thereby establishing a pioneering demonstration platform for the efficient cogeneration of clean water and energy from seawater.