N-doped Fe3O4 nanoparticles loaded-carbon foam for a highly efficient and recyclable desalination-photocatalysis solar evaporator

Solar-powered evaporation technology is a green and sustainable solution to freshwater scarcity. However, massive evaporation of seawater may lead to localized accumulation of pollutants in the waterbody, causing secondary pollution. Herein, we developed a recyclable solar evaporator with a synergistic effect of solar thermal evaporation and photocatalysis by introducing Fe3O4 nanoparticles (NPs) into carbon foam scaffold. The incorporation of Fe3O4 NPs can not only enhance the light absorption capability of carbon foam composite from visible to infrared regions, but also, the photocatalytic activity of the loaded Fe3O4 has been facilitated due to the dopant of N on Fe3O4 during the carbonization process. Additionally, the combined magnetic carbon foam (NFe3O4@CF) exhibits sustained stability, salt resistance and good recyclability, which can avoid secondary pollution. As a result, the integrated desalination-photocatalysis system achieved an evaporation efficiency up to 93.27 % under 1.0 solar irradiation, evaporation rate reached 1.5303 kg m- 2 h- 1 and simultaneously the degradation rate of organic pollutant reached more than 96 % within 1 h, which provides a feasible solution to alleviate global water/energy scarcity.