A Low-Content Ce-Doped NiFe2S4 Trimetallic Catalyst with Highly Efficient Activation of Peroxomonosulfate for Degradation of Organic Pollutant

In this paper, a low-content Ce-doped trimetallic sulfide catalyst (Ce–NiFe2S4) was prepared by the hydrothermal method. The prepared catalyst can improve the oxidant potential of peroxymonosulfate (PMS) to degrade rhodamine B (RhB) dye efficiently in a low dosage. In addition, Ce–NiFe2S4 possessed a magnetic property due to the contained nickel-iron elements. Therefore, the catalyst material has good separation and reusability characteristics. The factors influencing the degradation efficiency of rhodamine by a Ce–NiFe2S4-facilitated PMS oxidation system, such as initial solution pH, PMS dosage, catalyst dosage, and temperature were investigated. The results revealed that RhB can be degraded by 95 % in 30 min at the optimal conditions (100 mg/L catalyst, 200 mg/L PMS). The reaction rate would be further increased when the initial solution pH was 3 with the reaction temperature at 50°C. Furthermore, the quenching experiments verified that 1O2 made an important contribution to the degradation of pollutants as a main active species. SO4•– and •OH, to some extent, participated in the chemical degradation reaction. S2– promoted cycling of redox reactions between metal ions and PMS to ensure catalyst stability and reusability.