Synthesis of magnetic Z-scheme MoS2/CdFe2O4 composite for visible light induced photocatalytic degradation of tetracycline

The overuse and dissemination of antibiotics caused serious threats to the environment and public health. In this work, a molybdenum disulfide-magnetic spinel ferrite composite (MoS2/CdFe2O4) with a low bandgap was designed and prepared by a two-step hydrothermal method. Compared with MoS2, CdFe2O4 and other MoS2/CdFe2O4 composites, the 60% MoS2/CdFe2O4 composite showed best visible light induced photocatalytic activity towards tetracycline (TC) degradation reaction. More than 87% of TC (25 ppm) can be degraded under visible light till 120 min. The degradation of TC over the MoS2/CdFe2O4 composites followed the pseudo-first-order kinetics. The 60% MoS2/CdFe2O4 composite had largest apparent reaction rate constant of 11.36 x 10(-3) min(-1). Due to its magnetic property, the MoS2/CdFe2O4 composite with saturation magnetization value of 7.0 emu g(-1) can be separated easily from water and reused. Based on the band structure and active species analysis, a Z-scheme structure was formed in the MoS2/CdFe(2)O(4)composite, which accelerated photocatalytic oxidation. The hydroxyl radicals (OH) were detected under visible light irradiation and provided strong photocatalytic oxidation performance. This work may provide new ideas for designing visible light responsive and magnetic CdFe2O4 photocatalysts.