Metal-organic frameworks (MOFs) for the removal of emerging contaminants from aquatic environments

Abstract

Metal-organic frameworks (MOFs) have gained attention as promising materials for aqueous-phase sorptive removal of emerging contaminants (ECs). Attributes such as large adsorption capacity, high surface area, tunable porosity, hierarchical structure, and recyclability give MOFs an edge over conventional adsorbents. The poor stability of MOFs in water is a major challenge to their real-world environmental application. The performance of MOFs and their selectivity toward targeted pollutants for removal can be regulated by judicious selection of metal ion and organic linker. A range of water-stable MOFs (e.g., MIL-53, MIL-100, MIL-101, UiO-66, and MIL-125) and their composites with other materials have been reported to remove the ECs from water. The present review critically addressed the performance of MOFs for the adsorptive removal of different categories of ECs from water and the adsorption mechanisms involved. The performance of MOFs compared with other adsorbents has also been discussed. This body of rapidly developing research signifies the emerging importance of MOFs in environmental applications and provides a future direction for the development of treatment technology to effectively remove ECs from aqueous environments.