Solar-driven interfacial evaporation coupling with photo-Fenton of floating Prussian blue/polypyrrole/paper film for volatile organic compounds-containing wastewater treatment

Solar-driven water evaporation can generate clean steam through phase change and mass transfer processes. However, when dealing with volatile organic compounds (VOCs) contaminated water sources, VOCs tend to volatilize into the vapor during the evaporation process, making separation difficult. This issue can be effectively addressed by utilizing photo-Fenton technology to assist the solar-driven water evaporation process. A novel photothermal catalytic film was successfully prepared by incorporating Prussian blue (PB) and polypyrrole (PPy) onto a slow filter paper substrate. The photothermal conversion ability of PPy was further enhanced by PB, and the temperature increase induced by PPy accelerated the photo-Fenton catalysis process, indicating a synergistic action between photothermal evaporation and photo-Fenton catalysis. The film exhibited outstanding catalytic performances in degrading various VOCs in wastewater, including phenol, methyl orange, methylene blue, and rhodamine B. Notably, the film reached an impressive degradation rate of 99.5 % for methyl orange within 2 h. The assembled 2D interfacial evaporator achieved an evaporation rate of 1.58 kg m^-2h⁻¹ under one sun irradiation (1 kW m⁻²). After 40 cycles, the evaporation rate remained constant. This photothermal catalytic film effectively degrades VOCs while stably producing steam, demonstrating significant potential in the treatment of volatile organic wastewater.