Significant acceleration of Fe2+/ peroxydisulfate oxidation towards sulfisoxazole by addition of MoS2.Environ Res. 2020 Sep; 188:109692.ER
Activation of peroxydisulfate (PDS) by Fe2+ has been considered as an effective activation method to generate reactive oxygen species (ROS). However, the process is limited for the low production yield of ROS owing to the inefficient Fe3+/Fe2+ cycle. Herein, we demonstrated that Fe2+/PDS system in the presence of molybdenum sulfide (MoS2) was significantly efficient for the degradation of sulfisoxazole (SIX). As a co-catalyst in the Fe2+/PDS system, MoS2 could greatly enhance the Fe3+/Fe2+ cycle by the exposed Mo4+ active sites, which could also improve the PDS decomposition efficiency. As a result, the degradation efficiency of SIX in the MoS2/Fe2+/PDS system could reach to as high as 97.1% within 40 min, which was in distinct comparison with the 45.5% achieved by Fe2+/PDS system without MoS2. Besides, effects of various reaction conditions on SIX degradation were also evaluated during the experiments, including the dosages of MoS2, Fe2+, PDS and initial solution pH and the coexisting inorganic anions. In addition, both of sulfate radicals and hydroxyl radicals were identified as the dominant active species for SIX degradation by the radical scavenging experiments and verified by electron paramagnetic resonance (EPR). This study provides a promising idea for the degradation of organic contaminants in water treatment based on Fe2+/PDS process.