Solar-powered evadsorber: Integrated interfacial evaporation and photothermal-synergistic adsorption for freshwater production combined cesium extraction

High-efficiency desalination and selective cesium extraction from salt lake brine is critical to alleviate global freshwater scarcity and energy crises. Conventional evaporation and metal extraction systems lack synergistic integration between water transport, thermal management, and ion-selective enrichment. Herein, we report an integrated solar-driven interfacial evaporation and adsorption system—termed ‘Evadsorber’—based on a Prussian blue (PB)-modified nanofiber 3D network for concurrent desalination and Cs + capture. The hierarchical pore structure optimizes rapid water/ion transport, while PB's lattice cages serve as selective adsorption sites for Cs + . By introducing a cold evaporation interface to recover latent heat, we achieve a substantial evaporation rate enhancement from 3.25 to 6.06 kg·m −2 ·h −1 under 1-sun irradiation. Crucially, we demonstrate that photothermal evaporation generates dual thermal and concentration gradients, which synergistically drive Cs + diffusion and enrichment. This photothermal-synergistic adsorption process yields a record Cs + adsorption capacity of 233.45 mg·g −1 with exceptional ion selectivity under solar conditions-1.45 times higher than adsorption in darkness. Robust outdoor performance confirms the system's viability, establishing a new paradigm for concurrent freshwater production and critical metal extraction.