Thiol-Functionalized MIL-100(Fe)/Device for the Removal of Heavy Metals in Water

The preparation of a functional device based on a functionalized MIL-100(Fe) metal-organic framework for the solid-phase extraction of heavy metals is reported. By a simple and easy straightforward grafting procedure, a thiol-functionalized MIL-100(Fe) material (MIL-100(Fe)-SH) with a S/Fe ratio of 0.80 and a surface area of 840 m² g^-1 was obtained. MIL-100(Fe)-SH exhibited a higher Hg(II) extraction (96 ± 5%) than that of MIL-100(Fe) (78 ± 4%) due to the interaction between thiol groups and Hg(II) ions. For practical applications, the obtained MIL-100(Fe)-SH was integrated by a simple method to a 3D printed support based on a matrix of interconnected cubes using poly(vinylidene fluoride) as binder, obtaining a functional device that simultaneously acts as stirrer and sorbent. The developed device showed high efficiency for the removal of Hg(II), good reusability, and excellent performance for the simultaneous preconcentration and further detection and quantification of Hg(II), Pb(II), and As(V) in tap, well, and lake water samples.