MOFs-derived Co-Fe sulfides as highly efficient and stable catalysts to activate peroxymonosulfate for the degradation of trichlorophenol

Advanced oxidation processes activated by transition metal have attracted much attention for their excellent performance in the removal of organic pollutants, but the development of efficient and environmentally benign catalysts is still a significant challenge. In this work, carbon shell encapsulating Co/Fe sulfide nanoparticles (Co/ Fe@SCX) were synthesized by pyrolysis of the resorcinol-formaldehyde (RF) coated MIL-101 @ZIF-67 bimetal Metal-organic frameworks (MOFs). In the degradation of TCP, Co/Fe@SC600 exhibited the highest TCP removal rate (97.33%) and reaction rate constant (kobs) (0.169 min -1), as well as the mineralization rate of up to 60.19%. Compared to other prepared catalysts, Co/Fe@SC600 not only possessed excellent catalytic activity, but also exhibited the lowest Co ion leaching concentration, good stability and high resistance to environmental factors. Further studies showed that the non-radical pathway dominated by 1O2 contributed most to the TCP degradation, and the radicals also played the indispensable role. The potential TCP degradation pathways in the reaction system was also investigated by analyzing the intermediate products during the degradation process. Overall, this study may provide some interesting insights into the design of advanced catalysts.