Multiwall carbon nanotube decorated hemin/Mn-MOF towards BPA degradation through PMS activation

Abstract

Heterogeneous catalysis of organic contaminants in water has been a research concern. In this study, Fe-Mn bimetallic MOF was prepared with low concentration of hemin (0.18 mmol) as Fe source. Meanwhile, multiwall carbon nano tube (CNT) was further decorated on it. Finally, CNT-hemin/Mn-MOF with high peroxymonosulfate (PMS) catalytic effect was successfully synthesized. CNT-hemin/Mn-MOFs could catalytic PMS to degrade BPA within 30 min. This excellent catalytic effect was attributed to the reinforced redox reaction between Mn and the Fe of hemin, which would transfer more electrons. Furthermore, CNT and the N elements of hemin could promote electron transfer in this process. In addition, the degradation mechanism of BPA by CNT-hemin/Mn-MOF activated PMS system was also proposed. Results manifested that the non-free radical degradation pathway initiated by 1O2 and the free radical degradation pathway dominated by·OH were the main reasons for BPA degradation. Besides, a small amount of·SO4−,·O2- and direct electron transfer participated degradation. Two BPA degradation pathways have also been deduced. This work may broaden the horizons for the development of MOFs synthesis for the degradation of environmental pollutants.