Efficient accumulation integrated with selective degradation of micropollutants under irradiation of visible light by the size-exclusion effect of metal–organic framework

Developing multifunctional materials for efficiently removing pharmaceutical active compounds (PACs) in water matrix that coexisted with humic acid (HA) is in high demand. Water-stable metal-organic frameworks (MOFs) with tunable porous structures have aroused great attention as versatile adsorbents. However, further eliminating pollutants, especially in practical applications, needs more exploration. In this study, rational modification of UiO-66 (Ce) with a minimum amount of CdS could regulate the highly developed cavities and subsequently promote the selective interfacial degradation of four PACs, including non-steroidal anti-inflammatory drugs and antibiotics with lower concentrations (100 μg/L) detected by HPLC-MS/MS were selected as the model compounds. The adsorption ability of the composites was 11.84 ∼12.21 times higher than CdS, and the overall removal efficiency was 1.31 and 2.18 times higher than that of UiO-66 (Ce) and CdS, respectively, via h+ and •O2- generated in simulated HA-containing wastewater. This modification features excellent resistance towards HA (2 mg/L ∼ 10 mg/L) during adsorption and photocatalytic degradation effectively. In comparison, competitive anions (Cl-, SO42-, CO32-, HCO3-) with smaller sizes affect ROS formation significantly, indicating the possible exclusion effect of competitors by particular sizes. This study offers a facile strategy to remove PACs and HA-containing water effectively.