Different performances of zinc/cobalt-based zeolite imidazolate frameworks derivatives to effectively activate peroxymonosulfate for degradation of organic pollutants

Zeolite imidazolate frameworks materials (ZIFs, especially ZIF-8 and ZIF-67) used as catalysts for peroxymonosulfate (PMS) activation to generate reactive oxidative species (ROS), such as free radicals and singlet oxygen radicals, for the degradation of organic pollutants in the advanced oxidation processes (AOPs) have received much attention recently. The synthesis and modification methods of ZIF-8 and ZIF-67 were introduced in detail, particularly based on the specificity generated by the differences in the characteristics of the material itself. In additional, the modification of ZIF-8/ZIF-67 composites for activating PMS was systematically discussed for the first time. The feasibility and possible development directions of zinc-cobalt co-catalysis were proposed. Finally, the potential active sites of modified materials in the catalytic process were summarized, the degradation mechanism were elucidated, and the difficulties and challenges that ZIFs still need to face in activating PMS in the future were explained.