Core-shell bimetallic Fe-Co MOFs to activated peroxymonosulfate for efficient degradation of 2-chlorophenol

Based on two topologically distinct MOFs, the core–shell bimetallic MIL-101/ZIF-67 x (M/Z x ) were successfully prepared to activate the self-decomposition of peroxymonosulfate (PMS) for 2-chlorophenol (2-cp) degradation. The M/Z x not only inherited the merits of single-metal MOFs such as high surface area and pore volume, but also exhibited superior catalytic performance. In the M/Z x /PMS system, 90% of the 2-cp (100 mg/L) was removed within 10 min with a reaction rate of 0.241 min −1 . This observation was attributed to the synergistic catalysis of cobalt and iron active sites in M/Z x , which greatly promoted the Co 2+ /Co 3+ redox cycle, thereby enhancing the catalytic performance. Further investigation found that both radical and non-radical pathway jointly promote the degradation of 2-cp, and the singlet oxygen ( 1 O 2 ) mediated non-radical pathway serve a predominant role. Meanwhile, SO 4 ·- and · OH also accelerated this process. The possible degradation pathway was proposed by identifying the intermediates of 2-cp degradation. This work provides some new ideas for the design of multi-metal MOFs for environmental remediation.