[Carbonized Foam Supported Co₃O₄ Activated Peroxymonosulfate Towards Rhodamine B Degradation]

Co₃O₄ has received much attention because of its excellent performance in activating peroxymonosulfate. However, the practical application of Co₃O₄ has been seriously restricted by the problems of agglomeration of Co₃O₄, difficult separation, easy loss, and poor recycling. In this study, the CMF/Co₃O₄ heterogeneous catalyst was prepared using the hydrothermal method. The crystal structure and morphology of CMF/Co₃O₄ were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Rhodamine B (RhB) degradation was employed as a model test for evaluating potassium peroxymonosulfate (PMS) activation. The degradation rate of RhB can reach 98% in the catalyst dosage of 35 mg·L^-1, PMS concentration of 50 mg·L^-1, pH of 7, and RhB initial concentration of 10 mg·L^-1 after a 30 min reaction. The results showed that the degradation rate of RhB could be significantly improved by increasing the amount of CMF/Co₃O₄ heterogeneous catalyst and the mass concentration of PMS. The degradation rate of RhB can be inhibited by increasing the initial mass concentration of RhB and pH value. The process of degradation of RhB can be fitted by using the pseudo first-order kinetics model. The effect of temperature on the degradation rate of RhB conformed to the Arrhenius model, and the degradation process was a surface reaction-controlled process. The results of the free radical capture experiment showed that the sulfate radicals were the dominant active species for RhB degradation. After four cycles, the degradation rate of RhB still remained above 93% with CMF/Co₃O₄ catalyst.