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

Abstract

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.