Fast and efficient removal of mercury ions using zirconium-based metal–organic framework filter membranes

The mercury ions seriously threaten the environment and human health. It is desirable to remove mercury ions quickly and simply. Herein, the zirconium-based metal–organic framework (Zr-MOF) filter membranes for high efficiency mercury ions removing were in-situ prepared on the filter paper under mild conditions. Here, the Zr-MOF was constructed by coordination of Zr4+ ions and 2, 5-dimercaptoterephthalic acid (H2DMBD), which the free sulfhydryl group on the ligand is used to adsorb mercury ions. The prepared Zr-MOF filter membranes were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). The mercury removal efficiency of the filter membranes is as high as 97.8% within a few minutes. The high efficient removal efficiency is derived from the presence of sulfhydryl functional groups of MOF and the ultra-high specific surface area of the formed small-sized MOF particles on the filter membrane. Compared with other MOF membranes and the corresponding MOF powders, our membranes exhibit the short-term and high-efficiency removal abilities of the filter membranes. This work provides an insight for the preparation of high-performance MOF membranes.