Co nanoparticles modified N-doped carbon nanosheets array as a novel bifunctional photothermal membrane for simultaneous solar-driven interfacial water evaporation and persulfate mediating water purification.

Solar-driven interfacial water evaporation is an effective way to produce clean freshwater. However, it is still challenging that volatile organic compounds might enter the condensate in the evaporation process. Herein, we designed a novel bifunctional photothermal membrane (Co-N-C/CF) that can be applied for simultaneous water evaporation and persulfate mediating water purification. Due to the molecular thermal vibrations effect of carbon-based materials, plasmonic effect of Co NPs, the membrane exhibited an impressive water evaporation rate of 1.88 kg m−2 h−1 (1 sun irradiation). Furthermore, Co-N-C/CF could effectively activate persulfate for phenol (PE) removal through a non-radical reaction process. Experiments and density functional theory calculations illustrated that PE is favorable to be degraded while water molecules are easier to be converted into vapor in the photothermal evaporation process. Hence, the combination of persulfate-based oxidation and solar-driven water evaporation shows great application potential in the durable and efficient production of clean water. [Display omitted] • A novel bifunctional photothermal membrane (Co-N-C/CF) was successfully fabricated. • Co-N-C/CF was applied for water evaporation and PS mediating water purification. • Vertically aligned nanosheets array enhanced the absorption of sunlight. • Co NPs could provide electrons to the outer carbon layer of the Co-N-C/CF. • The weak interactions were graphically revealed by interaction region indicator. [ABSTRACT FROM AUTHOR]