A novel bifunctional evaporator for simultaneous steam generation and organics degradation by integrating electro-Fenton

Abstract

Solar interfacial evaporation (SIE) is a sustainable and environmentally-friendly water purification technology to address the global freshwater scarcity, but conventional SIE cannot purify water containing volatile organic compounds (VOCs). In this work, a dual functional evaporator was proposed to achieve efficient degradation of VOCs in water by in-situ production of H₂O₂ and reactive oxidizing species (ROS) during a Joule heating accelerated steam generation process through coupling SIE with heterogeneous electro-Fenton (he-EF). The results revealed that the dual functional evaporator exhibited a high evaporation rate of 1.62 kg m^-2h^-1 at a potential of -0.8 V vs. Ag/AgCl under 1.0 kW m^-2 light irradiation, which was 1.3 times that of the single interface evaporation process. Meanwhile, compared to a phenol removal efficiency of only 8.17% during the alone evaporation, almost no phenol residue was detected in the condensate. Even after 10 cycles of continuous operation, the phenol removal rate was still maintained at ∼ 98%, showing an outstanding stability and durability. Furthermore, for other VOCs (including Aniline, 1-Methyl-2-pyrrolidone, Dimethyl sulfoxide and N, N-Dimethylformamide), the dual functional evaporator also exhibited the degradation efficiency all exceeding 90%, indicating its excellent capability of removing various VOCs from actual water. Therefore, this study provided an efficient approach for supplying VOCs-free water and accelerating steam generation during the SIE processes.