The obvious advantage of amino-functionalized metal-organic frameworks: As a persulfate activator for bisphenol F degradation

In this study, two iron-based metal-organic framework compounds (MOFs), were used and compared as catalysts for persulfate (PS) activation to degrade bisphenol F (BPF). The outstanding advantage of using aminofunctionalized MOFs in the catalytic system was verified under different reaction conditions, and the mechanism was explored. The results indicated that NH2-MIL-101(Fe)/PS system not only had a wide pH application range, but also possessed an excellent catalytic performance towards interference from the coexisting anions and humic acid. Density functional theory (DFT) calculations showed that, compared with MIL-101(Fe), the -NH2 modification could significantly improve the electronic conductivity of NH2-MIL-101(Fe) by enhancing its Fermi level (-4.28 eV) and binding energy to PS (-1.19 eV). The free radical quenching experiments were combined with electron paramagnetic resonance (EPR) confirmed that free radicals (SO4 center dot-, center dot OH, O-2(-)center dot) worked together with the non-radical (O-1(2)) reaction to remove 91% BPF within 40 min in the NH2-MIL-101(Fe)/PS system. The two proposed BPF degradation pathway were related to hydroxylation, oxidation and ring cracking. The toxicity of the BPF degradation intermediates as well as its final products were also evaluated. (c) 2020 Elsevier B.V. All rights reserved.