Structure tunning of MoS2@Fe3O4 by modulating electron density for enhanced Fenton-like PMS activation: Accelerated Fe (III)/Fe (II) cycle for efficient micropollutants removal

1T-MoS 2 is a promising material for regulating the electronic structure of Fe-based catalyst to enhance PMS activation, due to the higher chemical reactivity of the basal plane with excellent intrinsic electronic properties. Herein, an excellent MoS 2 @Fe 3 O 4 by using 1T- MoS 2 as support to tune electronic structure, labeling as 1T-MoS 2 @Fe 3 O 4 , was successfully synthesized for faster and enhanced micropollutants degradation via Fenton-like peroxomonosulfate (PMS) activation. The composite showed remarkable catalytic performance, as evidenced by a removal rate of 1.12 × 10 −1 min −1 for caffeine, which was 4.50 times higher than that of 2H-MoS 2 @Fe 3 O 4 , attributed to the robust capacity for Fe (II) regeneration. The efficiency of the 1T-MoS 2 @Fe 3 O 4 /PMS system was affected by pH, PMS and catalyst dosages, as well as water chemistry. Additionally, the potential mechanism for PMS activation was explored, showing that O 2 • were the dominant reactive oxygen species (ROS) generated in the system due to the electron-rich O sites on the composite, and electron transfer processes play an important role during PMS activation. The Mo (IV) active sites facilitated accelerated Fe (III)/Fe (II) cycle, which promoted the rapid PMS activation. Excellent degradation of micropollutants (MPs) mixture in real secondary effluent was achieved by 1T-MoS 2 @Fe 3 O 4 /PMS system. The possible degradation pathways of caffeine (CAF), ibuprofen (IBP), and carbamazepine (CBZ) were also investigated. This study offers a new perspective on MoS 2 as a co-catalyst/support within Fenton-like system. • 1T-MoS 2 prevented the Fe 3 O 4 aggregation and tuned the electronic structure of the composite. • Excellent catalytic performance of the composite is attributed to Fe (III) lower electron density and abundant e – of 1T-MoS 2 . • Mo (IV) active sites in eletron-abundant 1T-MoS 2 promoted and expedited Fe (II) regeneration. • Both reactive oxygen species and electron transfer processes participated in CAF degradation.