Biomass Hydrogel Solar-Driven Multifunctional Evaporator\nfor Desalination, VOC Removal, and Sterilization

Solar-driven photothermal interfacial\nevaporation technology is\ncurrently perceived as one of the most green and effective freshwater\nproduction strategies available. However, when dealing with actual\ncomplex water bodies, it remains a challenge to combine steam generation\nwith removing volatile organic compounds (VOCs) and inactivating bacteria\nat the same time to achieve multiple water purification effects. In\nthis paper, a solar evaporator (SA/CCC/Cu<sup>2+</sup>) integrating\nphotothermal and photocatalytic effects was successfully constructed\nby using a Cu<sup>2+</sup> cross-linked biomass sodium alginate (SA)\nhydrogel as the basic skeleton and carbonized carboxymethyl chitosan\n(CCC) embedded internally as the photothermal material. During the\nsolar evaporation process, the SA/CCC/Cu<sup>2+</sup> evaporator successfully\nrealized the separation of distilled water from bulk water containing\nVOCs, achieving the VOC removal efficiency of 96.77% while maintaining\nan evaporation rate of 2.54 kg m<sup>–2</sup> h<sup>–1</sup>. In addition, it demonstrated remarkable capacity in inactivating <i>Escherichia coli</i> (<i>E</i>. <i>coli</i>), eliminating 100% of the bacteria within 40 min. With the rapid\nevaporation rate and impressive water purification effect, this design\nis anticipated to be a new path for solar-driven interfacial evaporative\nfreshwater production.