Activation of Peroxymonosulfate by Co-Metal–Organic Frameworks as Catalysts for Degradation of Organic Pollutants

Two novel Co-based metal–organic frameworks, namely, [Co3(H3bpt)2(1,4-bimb)3(H2O)2]·2DMF·H2O (CUST-560) and
[Co3(H3bpt)2(4,4′-tmdp)2(H2O)2]·2CH3OH·H2O (CUST-561) (H3bpt = 3,4′,5-biphenyltricarboxylic
acid, 4,4′-tmdp = 4,4-trimethylenedipyridine, and 1,4-bimb
= 1,4-bis­((1H-imidazol-1-yl)­methyl)­benzene), were
synthesized under hydrothermal conditions and characterized. In this
study, by adjusting several experimental parameters including catalyst
dosage, PMS volume, temperature, and the initial value of pH, PMS
activation toward two cationic dyes and two anionic dye degradations
was systematically examined. Radical scavenging experiments revealed
that SO4·– is considered
to act as the paramount reactive oxygen species in the oxidation process.
The Co­(III)/Co­(II) recycle of CUST-560 and CUST-561 is able to carry
out an effective electronic transfer to PMS, facilitating the reaction
process; thus, an eminent catalytic property has emerged. Consequently,
the original material as-synthesized is thought to be a splendid activator
to peroxymonosulfate activation for extermination and decolorization
of dyes.