Exploring a thiol-functionalized MOF for elimination of lead and cadmium from aqueous solution

A thiol-functionalized metal organic framework material (called HS-mSi@MOF-5) was successfully prepared by the thiol modification which taking the silica gel layer as a medium, on the basis of zinc based metal organic framework (MOF-5) synthesized by hydro-thermal method. The novel material was characterized by Fourier transfer infrared spectroscopy, scanning electron microscopy and X-ray powder diffraction. It was also investigated to remove lead and cadmium ions from aqueous solution. In view of adsorption capacity, and adsorption rate, HS-mSi@MOF-5 was shown to be a more convenient and effective adsorbent (312.5 mg/g; 652 g/mg.min(0.5)) than unmodified MOF-5 (211 mg/g; 4.2 g/mg.min(0.5)). Besides, in the hydrostability test, unmodified MOF-5 would leak its own component when present in add solution, whereas the thiol-functionalized material was stable owing to its synthesis process taking the silica gel layer as a medium. At last, electrostatic attraction and the thiol coordination interaction with potentially toxic metals played vital roles in the adsorption of lead and cadmium ions on HS-mSi@MOF-5. (C) 2016 Elsevier B.V. All rights reserved.