Tailoring zirconium-based MOF architectures for uptaking targeted micropollutants with high risk: critical role of porphyrin ligands in adsorption-catalysis processes

Global water scarcity and the persistent threat of emerging organic contaminants demand advanced solutions for wastewater treatment. Metal-organic frameworks (MOFs), particularly water-stable zirconium-based metal organic frameworks (Zr-MOFs), offer exceptional promise due to their high surface areas, tunable pore architectures, and catalytic potential. Herein, we systematically investigate three representative Zr-MOFs, UiO-66, NH₂-UiO-66, and PCN-222, for the adsorption and solar-driven photocatalytic degradation of multiple high-risk pharmaceuticals and personal care products (PPCPs), especially towards halogenated organic compounds. Notably, porphyrinic ones demonstrate superior performance, attributed to their hierarchical mesoporous structure and unique porphyrinic linker. Comprehensive characterization was conducted to explore the reaction mechanism. Upon light irradiation, an efficient ligand-to-cluster charge transfer (LCCT) mechanism within PCN-222 facilitates spatial separation of electron-hole pairs and the generation of reactive oxygen species (¹O₂), driving efficient oxidative degradation of the adsorbed pollutants. This work provides an integrated adsorption–photocatalysis strategy using a series of robust Zr-MOFs for the effective removal of organic micropollutants in water.