Efficient degradation of 2,4-dichlorophenol in aqueous solution by peroxymonosulfate activated with magnetic spinel FeCo2O4 nanoparticles.

Magnetic spinel FeCo2O4 nanoparticles (NPs) were synthesized and proposed as a catalyst of peroxymonosulfate (PMS) for the degradation of 2,4-dichlorophenol (2,4-DCP). The catalyst was characterized by XRD, TEM, XPS, nitrogen adsorption-desorption isotherms, and magnetization curve. In addition, the effects of parameters, such as initial pH, PMS dosage, FeCo2O4 addition, and initial concentration of 2,4-DCP were studied. The results showed that FeCo2O4 NPs exhibit good properties for the degradation and mineralization of 2,4-DCP, achieving 95.8% and 44.7% removal of 2,4-DCP and TOC, respectively, within 90 min under reaction conditions of 4 mM PMS, 0.06 g L-1 FeCo2O4, 100 mg L-1 2,4-DCP, pH = 7.0, and T = 30 °C. Furthermore, SO4- and HO were main radical species in the reaction system was explored. The 2,4-DCP degradation efficiency could reach 91.8% even after FeCo2O4 NPs were used for the fifth run. Moreover, the degradation efficiencies of metronidazole (MNZ), methylene blue (MB), and rhodamine B (RhB) could reach 74.8%, 86.7%, and 96.1% under the same reaction conditions, respectively. Results revealed that the FeCo2O4/PMS system shows potential for degrading contaminants in the environment.