Integrated Solar Evaporator with Salt Resistance and Lipophobicity Derived from Waste Newspapers for Efficient Desalination

Solar steam generation (SSG) is an effective way to mitigate the freshwater crisis. However, challenges still remain in scalable preparation, cost-effectiveness, and expanding the scope of practical applications for photothermal materials. Herein, a biomass-based solar steam generator (named OR-INP) with salt-resistant, oil-repellent, and anti-fouling performances is fabricated by grafting poly(ionic liquid)s onto celluloses from waste newspapers and then conducting oil-repellent modification. Benefiting from the broad solar absorption in the wet state (ca. 92%), low thermal conductivity (0.1108 W m–1 K–1), and strong hydrophilic and oleophobic properties, the solar evaporation efficiency is as high as 93.25% for pure water, 84.96% for 20 wt % NaCl, and 78.46% for 5 wt % oily wastewater, under 1 sun irradiation. Moreover, the aerogel still has excellent purification effects on solutions which contain organic dyes, heavy metal ions, or bacteria. Therefore, combining the merits of salt resistance, oil repellency, and wastewater treatment, this work develops the prospect of employing waste biomass resource-based photothermal materials and expands the practical application range of biomass-based evaporators.