Enhanced peroxymonosulfate activation via MOF-derived bimetal core-shell Co-Fe@NC hybrids to degrade emerging pollutants
Hui Li, Xinlei Ren, Wenxue Pan, Shiting Zhu, Jin Zhang, Zhiyuan Yang, Qian Liu, Yueying Wang, Yujing Huang, Lin Guo, Minghui Xiang
Abstract
The reasonable control of the structure of metal–organic frameworks (MOFs) is a promising strategy for improving their peroxymonosulfate (PMS) activation activity. In this study, ZIF-67 @ZIF-8 was used as a template to prepare bimetallic core–shell Co-Fe@NC via Fe doping and high-temperature carbonization . Co-Fe@NC maintained the core–shell structure of the original MOF, in which cobalt was uniformly distributed in the nitrogen-doped graphite carbon skeleton and the surface of the graphite carbon skeleton was covered with iron. With the synergistic effect of the nitrogen-doped graphite carbon skeleton, iron, and cobalt, 100% of tetrabromobisphenol S (TBBPS) was removed in 60 min with k obs = 0.062 min −1 in [email protected]/PMS system. The addition of iron increased the graphitization degree with I D /I G value increased from 0.98 (Co@NC) to 1.034 ([email protected]) and electron transfer rate of the carbon skeleton. Besides, the Co leaching was effectively attenuated from 1.86 mg/L(Co@NC) to 0.78 mg/L ([email protected]) by the core-shell structure and bimetal strategy. Both O 2 · - and 1 O 2 contributed to the degradation of TBBPS according to quenching experiments. TBBPS was deeply degraded into small-molecule compounds through three degradation pathways by the [email protected]/PMS system. This study provides a new strategy for designing highly efficient bimetal–carbon composites for environmental remediation.