Removing Perfluoro Pollutants PFOA and PFOS by Two-Pronged Design of a Ni8-Pyrazolate Porous Framework

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)35107–35116
Journal / PublicationACS Applied Materials & Interfaces
Volume15
Issue number29
Online published13 Jul 2023
Publication statusPublished - 26 Jul 2023

Abstract

Inspired by the practical need to remove persistent perfluoro pollutants from the environment, we leverage cutting-edge crystal engineering approaches. For this, we set our eyes on a recent porous coordination framework system based on the Ni8-oxo cluster and pyrazolate linkers as it is known for its stability to bases and other harsh environmental conditions. Our designer linker molecule here features (1) pyrazole donors masked by t-butyloxycarbonyl and (2) ethynyl side units protected by triisopropylsilyl groups. The former solvothermally demasks to assemble the Ni8-pyrazolate framework, in which the triisopropylsilyl groups can be post-synthetically cleaved by guest fluoride ions to unveil the terminal alkyne group (−CCH). The ethynyl groups of the framework solid offer versatile reactions for functionalization, as with perfluorophenyl azide (via a click reaction) to afford the two prongs of the 1,2,3-triazole base unit and the perfluoro unit. Together, these two functions make for an effective adsorbent for the topical acid pollutants of perfluorooctanoic acid and perfluorooctanesulfonic acid, with a high apparent rate constant (kobs) of 0.99 g mg-1 h-1 and large maximum uptake capacity (qmax) of 268.5 mg g-1 for perfluorooctanoic acid and kobs of 0.77 g mg-1 h-1 and qmax of 142.1 mg g-1 for perfluorooctanesulfonic acid. © 2023 American Chemical Society.

Research Area(s)

  • in situ deprotection, metal−organic framework, Ni8-pyrazolate system, perfluorinated pollutants adsorption, post-synthetic modification