MoS 2 boosts the Fe 2+ /PMS process for carbamazepine degradation

Activation of peroxymonosulfate (PMS) by Fe 2+ is a green oxidation process for degradation of organic contaminants. However, the formation of iron mud and low PMS utilization lead to the decreased oxidation efficiency. In this work, commercial MoS 2 particles were used as the catalyst for boosting the Fe 2+ /PMS process for carbamazepine (CBZ) removal. The CBZ removal efficiency by the MoS 2 /Fe 2+ /PMS process was significantly enhanced, increasing to 6.5 times that of the Fe 2+ /PMS process. The Fe 3+ was reduced to Fe 2+ by the exposed Mo 4+ on the surface of MoS 2 , leading to the enhanced PMS utilization rate and increased Fe 2+ concentration. The relative intensity of DMPO-HO• and DMPO- SO 4 – • followed the order of MoS 2 /PMS < Fe 2+ /PMS < MoS 2 /Fe 2+ /PMS, also suggesting the enhanced oxidation activity with the addition of MoS 2 in the process of Fe 2+ /PMS. The commercial MoS 2 had good stability shown by the CBZ removal efficiency remaining almost unchanged during 8-time cycling use. Finally, a possible CBZ degradation pathway was proposed for helping understand the oxidation mechanism of the MoS 2 /Fe 2+ /PMS process.