Solar-Powered Water Depollution Through a Bioinspired Device Based on ZIF-8 Loaded Macroporous Hydrogels Prepared via...

Water pollution poses a constant threat to the environment and is one of the central causes for global shortage of clean water. Metal-Organic Frameworks (MOFs) have emerged as highly efficient adsorbents; however, their application is limited by their common production as fine powders, which hinders recovery and reuse. Here, we report a bioinspired strategy to overcome this limitation by embedding high loadings of ZIF-8 microparticles (up to 90 wt%) within macroporous polysaccharide hydrogels prepared via ice-templating and topotactic Ca^{2 +} crosslinking. The resulting monoliths exhibit highly aligned microporous channels and homogeneously distributed ZIF-8 particles whose crystallinity and microporosity are preserved. The polysaccharide/ZIF-8 hydrogel showed superior adsorption for methylene blue (MB) and methyl orange (MO) compared to bare polysaccharide hydrogel, while being easier to recover and recycle than ZIF-8 powder offering recyclability and structural integrity over multiple cycles. Under simulated solar irradiation, the hydrogels achieve up to 76% degradation of MB within 2 h. Finally, integration of a carbon-based paper on top of the hydrogel, working as a highly efficient vapor generator, drives the water transport through the device, enabling the design of a solar-powered depollution device that simultaneously purifies contaminated water and generates clean condensed water. This scalable, eco-compatible approach opens new perspectives for multifunctional MOF-biopolymer architectures in sustainable water treatment technologies.