Targeted Adsorptive Removal of Nonsteroidal Anti-inflammatory Drugs for Water Purification Using Nanoporous Zr-Based Metal-Organic Framework Microcubes

Chemically synthesized drugs used in the industry are associated with potential environmental risks. Herein, we report the targeted adsorption of nonsteroidal anti-inflammatory drugs, with and without a carboxylic acid group, using a water-stable Zr-based porphyrinic metal-organic framework (MOF), PCN-224. Nanoporous PCN-224 contains interaction sites for drugs and thus enables the removal of organic pollutants. The removal efficiency of NPX and IBP was 96 and 94%, but PCN- 224 removed only 37% of SMX from water. The apparent difference in the adsorption efficiency of PCN-224 indicates that the carboxylic acid functional groups in drugs strongly interacted with the open metal sites of the PCN-224 Zr6 node via coordination bonding, resulting in a high adsorption capacity. This discovery provided a practical approach for the selective adsorptive removal of various other drugs with carboxylate groups.