MOF-derived CoFe₂O₄/FeS₂ Z-type heterojunctions for efficient degradation of tetracycline by visible-light activation of persulfate

CoFe₂O₄ was successfully prepared by calcination of bimetallic MOF precursors, and CoFe₂O₄/FeS₂ nanocomposites were prepared by compounding it with FeS₂. The catalysts were characterized for their photocatalytic ability using tetracycline (TC) as a target contaminant. The high adsorption due to the wide specific surface area of MOF-derived CoFe₂O₄/FeS₂ led to its excellent photocatalytic performance. Furthermore, the optimum dosages of catalyst and persulfate in the M-CFO/FeS₂/Na₂S₂O₈/Vis system were determined. The variation of catalytic performance as a function of pH was also investigated. The degradation mechanism studies assisted by ESR technique and heterojunction structure analysis confirmed the Z-type heterojunction formation and generation of sulfate as well as superoxide free radicals, which played the main species responsible of TC degradation.