Fabrication of FeOCl/MoS2 catalytic membranes for pollutant degradation and alleviating membrane fouling with peroxymonosulfate activation

The combination of advanced oxidation (AOPs) and membrane separation technology provides a prospect for catalyst recovery and alleviation of membrane fouling. Herein, we prepared FeOCl/MoS2 catalysts for activating peroxymonosulfate (PMS) by a simple partial thermal decomposition method. Then, the FeOCl/MoS2 was immobilized onto a polyvinylidene fluoride (PVDF) membrane coated by polydopamine (PDA) through vacuum filtration. FeOCl/MoS2 can remove 96.9% of rhodamine B (RhB) within 5 min. Notably, with a pH range from 3 to 9, FeOCl/MoS2 exhibited high catalytic efficiency. Besides, the surface hydrophilicity of the PVDF membrane was significantly improved by the modification. The flux recovery rate (FRR) of the modified membrane reached 97.6%, which was 42.7% higher than that of the pristine membrane. With dead-end filtration, 72.2% of the pollutants can be removed. After 5 runs, the fabricated FeOCl/MoS2 membrane displayed good stability and high efficiency. The analysis of the mechanism showed that adding MoS2 to FeOCl can promote the reduction of Fe3+ to Fe2+ through the oxidation of Mo4+ to Mo6+. The active species in this system were identified as SO4-•, •OH, O2-•, and 1O2. SO4-• and 1O2 were dominant. This research provides a new strategy for the development and application of membrane separation technology.