Electrochemical-enhanced MoS2/Fe3O4 peroxymonosulfate (E/ MoS2/Fe3O4/PMS) for degradation of sulfamerazine

Seeking effective methods to degrade organic pollutants has always been a hot research field. In this work, MoS2/Fe3O4 catalyst was synthesized by hydrothermal method with MoS2 as carrier to construct an advanced oxidation system of electrochemical enhanced MoS2/Fe3O4-activated peroxymonosulfate (E/MoS2/Fe3O4/PMS). The materials were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The degradation efficiency of sulfamerazine (SM1) by E/MoS2/Fe3O4/PMS system was investigated and reaction mechanism was explored. The results showed that the removal rates of SM1 within 30 min were 31%, 20% and 89% with Fe3O4, MoS2 and MoS2/Fe3O4 as catalysts, respectively. The characterization results revealed that Fe(III) on the surface of Fe3O4 was reduced to Fe(II) and Mo(IV) was oxidized to Mo(VI) in the presence of MoS2. The synergistic effect between Fe3O4 and MoS2 enhanced the PMS decomposition and improved the SM1 removal efficiency. Free radical quenching experiments showed that SO4-⋅, ·OH, O2· and 1O2 were all involved in the degradation of SM1, and the effect of 1O2 was more significant than other active substances. Low concentrations of Cl- and humic acid (HA) had no significant inhibitory effect on the degradation of SM1, while HCO3- had a significant inhibitory effect on the E/MoS2/Fe3O4/PMS system. In addition, catalyst cycling experiments showed that MoS2/Fe3O4 maintained good stability before and after the catalytic reaction process.