Electrochemical-enhanced MoS/FeO peroxymonosulfate (E/ MoS/FeO/PMS) for degradation of sulfamerazine.

Seeking effective methods to degrade organic pollutants has always been a hot research field. In this work, MoS/FeO catalyst was synthesized by hydrothermal method with MoS as carrier to construct an advanced oxidation system of electrochemical enhanced MoS/FeO-activated peroxymonosulfate (E/MoS/FeO/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/MoS/FeO/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 FeO, MoS and MoS/FeO as catalysts, respectively. The characterization results revealed that Fe(III) on the surface of FeO was reduced to Fe(II) and Mo(IV) was oxidized to Mo(VI) in the presence of MoS. The synergistic effect between FeO and MoS enhanced the PMS decomposition and improved the SM1 removal efficiency. Free radical quenching experiments showed that SO⋅, ·OH, O· and O were all involved in the degradation of SM1, and the effect of O 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 HCO had a significant inhibitory effect on the E/MoS/FeO/PMS system. In addition, catalyst cycling experiments showed that MoS/FeO maintained good stability before and after the catalytic reaction process.