Boosting Fe (II) generation in MOFs under visible-light irradiation for accumulated micropollutants decomposition

The development of engineered nanomaterials has aroused great attention in controlling the existence of toxic micropollutants. However, their performance in complex environmental matrices is frequently neglected. Highly efficient enrichment coupled with synergistic degradation with low concentrations is challenging but significant in practical industrial applications. In this study, a large group of active pharmaceutical compounds (PACs) at environmentally relevant concentrations ∼μg/L were rapidly extracted in core-shell MIL-100 (Fe), followed by effective degradation during the visible-light photo-Fenton process in situ. Unexpectedly, in natural secondary wastewater, adsorption capacities were inhibited (2-50 % decreased after 60 min), while the degradation kinetics of eight PACs were remarkably promoted (1.42-2.92 times higher). Under neutral pH, the accumulated pharmaceuticals within cages were effectively decomposed by •OH and 1O2, mainly derived from visible-light-induced reduction of Fe (III)-cluster and the generation of ROS. The structural parameters (log Kow) were closely correlated to the adsorption behavior (R2 = 0.74), which remarkably facilitated the degradation. The powder was loaded onto the PTFE/ultrafiltration membrane in a flow-through reactor. The targeted PACs were rapidly degraded over the self-cleaning surface under visible light irradiation, implying a promising future for industrial application.