Metal–organic framework-derived carbon-based evaporator for activating persulfate to remove phenol in interfacial solar distillation

Interfacial solar distillation (ISD) can markedly improve the efficiency of photothermal seawater desalination, but the migration of semi-volatile organic compounds (SVOCs), such as phenolic pollutants, during the distillation process is a serious threat to the safety of water quality. A sulfate radical-based advanced oxidation process is introduced into ISD for SVOCs removal due to low cost, strong anti-interference capability, and high degradation efficiency. In this work, MOF-derived Fe@C evaporators with high Fenton-like catalytic performance were prepared by calcination of Fe-MOFs on metasequoia wood blocks. The results showed that Fe@C-700 possessed abundant active sites, and the phenol removal rate reached 95% under 5 sun. Free radical trapping experiment and EPR measurements confirmed the presence of both radical and non-radical pathways in the system with 1O2 and O2·- being the main active species. This work provides a feasible solution for the design and application of iron-based catalysts based on MOFs to the ISD process, and also discusses the synergistic effect between ISD and persulfate activation for achieving high quality distilled water.