Spherical Bi4O5I2/MoS2 QDs Nanocomposites Activate Persulfate to Degrade Tetracycline Under Visible Light

Photocatalytic activation of persulfate is considered to be a promising purification technology. In this study, a novel nanospherical composite material is synthesized by loading MoS2 Quantum Dots on Bi4O5I2. MoS2 Quantum Dots enhance the activity of the composite material and separation efficiency of electrons and holes. Meanwhile the composite material demonstrates a strong photocurrent response by optoelectronic analysis. In addition, the light absorption range is further expanded. Based on the improvement of photoelectric properties and light absorption performance, the BM0.5%/PS/Vis system exhibits the most excellent performance with a degradation rate of 69.7% for tetracycline within 60 min. The degradation mechanism is verified through free radical capture experiments, the radicals involve in degradation are <middle dot>OH, <middle dot>SO4-, <middle dot>O-2(-) and O-1(2). The possible degradation pathway of tetracycline is proposed by liquid chromatography-mass spectrometry (LC-MS). This work is expected to provide a research direction for the application of modified bismuth halide in PS activation.