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.