Efficient three-dimensional electrochemical degradation of alizarin red by CeO₂-MnO₂/NF particle electrode synergized...

In this study, nickel foam-loaded Mn and Ce bimetallic oxide composites were successfully synthesized as particle electrodes by a hydrothermal method and synergized with ozone for the efficient degradation of alizarin red (AR), a typical anthraquinone dye. The effects of common factors on the degradation rate of alizarin red were investigated. The optimal experimental conditions were derived as applied voltage = 3.5 V, initial pH = 5.5, NaCl concentration of 4.5 g/L, and initial dye concentration of 20 mg/L. The particle electrode had a high cyclic stability after five cycles. The active sites of the dye molecular structure were analyzed in combination with the Fukui function, and the degradation pathway of alizarin red was proposed on this basis. By comparing the degradation effect of alizarin red under three different systems of O₃, 3DER and 3DER-O₃, it was confirmed that the three-dimensional electrode has a good synergistic effect in conjunction with ozone. Finally, the degradation mechanism of alizarin red under the CeO₂-MnO₂/NF synergistic ozone system was derived, in which the single linear oxygen (¹O₂) played a major role in the degradation process.