Dual pathway reduction of Mo4+ and photogenerated electrons restore catalytic sites to enhance heterogeneous peroxymonosulfate activation system

Inefficient reduction of trivalent transition metal ions is an urgent factor limiting the rate of heterogeneous persulfate activation. A novel strategy is proposed for the first time to enhance catalytic center renewal by simultaneously introducing photogenerated electrons and reductive sites. Magnetically separable CoFe2O4 nanoparticles/flower-shaped MoS2 (CNxFM1-x) composite catalyst was synthesized by a simple self-assembly method. Experimentation and quantum chemical calculations show that MoS2 not only provides reducing sites for Co3+/Fe3+, but also forms type II heterojunction with CoFe2O4 to supply photogenerated electrons. This system achieves a chloroquine degradation efficiency of 98.6 % in 12 min with a rate constant of 0.3395 min−1. The dual pathway reduction of MoS2 promoting the regeneration of the catalytic center was the main reason for the strong pollutant degradation capacity. We also found that the (2 2 2) crystal plane of CoFe2O4 has optimal adsorption and activation for PMS by calculating Eads and lO-O.