Rapid and efficient removal of toxic ions from water using Zr-based MOFs@PIM hierarchical porous nanofibre membranes

The development of new adsorbent materials to improve adsorption capacity and selectivity constitutes a significant research direction for removing toxic ions from water. In this study, a series of Zr-based metal–organic framework hierarchical porous nanofibre membranes (MOFs@PIM-W) was designed and successfully synthesised, and their adsorption properties and mechanism for fluoride ions in water were investigated. The formation of Zr–F bonds in Zr-based MOFs is a primary reason for the rapid, effective, and stable removal of fluoride ions from water. Moreover, in contrast to common powder adsorbents and the conventional static adsorption process, the obtained hierarchical porous nanofibre membranes improve the removal rate of fluoride ions, which may be attributed to the formation of hierarchical porous structures. Specifically, by modifying the types of MOFs, the obtained nanofibre membranes can effectively remove Hg(II) ions from water under a wide range of pH environments (pH = 2–10) with a removal rate of up to 99 %. This indicates that the hierarchical porous design of nanofibre membranes incorporated with their specific adsorption provides a viable option for rapidly and efficiently removing toxic ions from water.