Enhanced Heterogeneous Catalytic Activity of Peroxymonosulfate for Rhodamine B Degradation via a Co^II-Based Metal–Organic Framework

Abstract

A stable metal-organic framework with the formula {[Co(BBZB)(IPA)]·H₂O}<i>_n</i> (<b>JXUST-23</b>, BBZB = 4,7-bis(1<i>H</i>-benzimidazole-1-yl)-2,1,3-benzothiadiazole and H₂IPA = isophthalic acid) was constructed by incorporating Co²⁺ ions and two conjugated ligands under solvothermal conditions. <b>JXUST-23</b> takes a dinuclear cluster-based layer structure with a porosity of 2.7%. In this work, <b>JXUST-23</b> was used to activate peroxymonosulfate (PMS) to degrade rhodamine B (RhB), a difficult-to-degrade pollutant in water. Compared with pure PMS or <b>JXUST-23</b>, the <b>JXUST-23</b>/PMS system displays the best degradation ability of RhB in neutral solution. When the mass ratio of <b>JXUST-23</b> to PMS was 2:3, 99.72% of RhB (50 ppm) was removed within 60 min, and the reaction rate was 0.1 min^-1. Furthermore, free radical quenching experiments show that SO₄^•- was the main free radical during the process of RhB degradation. In addition, <b>JXUST-23</b> exhibits good reusability for the degradation of the organic dye RhB, making it a potential candidate for environmental remediation.