Magnetic Co-Co Prussian blue analogue catalyst for peroxymonosulfate activation to degrade organic dye

In this study, the Fe3O4/Co3[Co(CN)6]2 composite catalyst was synthesized by co-precipitation method. The morphology and the structure of Fe3O4/Co3[Co(CN)6]2 composites were characterized by XRD, FTIR, SEM, TEM, EDS, XPS, VSM. The results showed that the removal rate of RhB (10 mg/L) reached 99.5% in 40 min in the 0.4-Fe3O4/Co3[Co(CN)6]2 (200 mg/L) + PMS (50 mg/L) system with a pseudo first-order degradation rate constant (k) of 0.121 min−1 , which is nearly 2.16 times of that (0.0561 min−1) in the Co3[Co(CN)6]2 + PMS system and 18.9 times of that (0.0064 min−1) in the Fe3O4 + PMS system. The observed synergistic catalysis between Fe3O4 and Co3[Co(CN)6]2 in Fe3O4/Co3[Co(CN)6]2 enhanced the degradation of RhB. The electron paramagnetic resonance (EPR) analysis and quenching experiment indicated that SO4− and OH played important roles in the degradation process of RhB. A synergistic catalytic mechanism of PMS activation by Fe3O4/Co3[Co(CN)6]2, which mainly involves the enhanced Co2+/Co3+ cycle by Fe2+ donated electrons, was proposed. In summary, owing to its easy preparation, excellent catalytic activity, and reusability, the Fe3O4/Co3[Co(CN)6]2 composite catalyst is a good candidate for remediation of contaminated water.