Peroxymonosulfate activation by magnetic CoNi-MOF catalyst for degradation of organic dye

In this work, Fe₃O₄/CoNi-MOF was synthesized by a simple solvothermal method. The catalytic performance of 0.2-Fe₃O₄/CoNi-MOF toward PMS activation was studied by degradation of 20 mg/L methylene blue (MB). The results indicated that 0.2-Fe₃O₄/CoNi-MOF had good catalytic ability, the removal rate of MB was 99.4% within 60 min with 125 mg/L PMS and 150 mg/L catalyst. Quenching experiment and electron paramagnetic resonance (EPR) analysis revealed that the singlet oxygen (¹O₂), superoxide radical (•O₂^-) and sulfate radical (SO₄^•-) played a crucial role in the catalytic degradation process. Meantime, mechanism of PMS activation by 0.2-Fe₃O₄/CoNi-MOF was proposed, the electrons donated by Fe²⁺ can also enhance the Co-Ni cycles. In conclusion, Fe₃O₄/CoNi-MOF composite catalyst has the advantages of simple preparation, excellent catalytic activity and reusability, which is an effective catalyst for water pollution control.