A novel persulfate activation strategy by double Z-scheme Bi2O3/CuBi2O4/BiOBr heterojunction: Non-radical dominated pathway for levofloxacin degradation

Persulfate advanced oxidation technology (PS-AOPs) is known as a novel wastewater treatment method. Considering the poor self-stability of Bi2O3/CuBi2O4, we synthesized Bi2O3/CuBi2O4/BiOBr ternary composite material and established the non-radical pathway-dominated peroxymonosulfate (PMS) activation system. The study indicated that BiOBr promoted electron migration on the material surface. Bi2O3/CuBi2O4/BiOBr/Vis/PMS system exhibited excellent catalytic performance (86.83 % within 100 min), significantly higher than Bi2O3/CuBi2O4 (63.19 %) and BiOBr (60.35 %). Furthermore, it has strong catalytic activity and adaptability to various environmental conditions. By quenching experiments and EPR analysis, O-2(-)center dot and 1O(2) were the main active species. Finally, possible degradation pathways and intermediates were predicted through liquid mass spectrometer (LC-MS), and toxicity analysis was conducted on levofloxacin (Lev) and intermediates. The degradation mechanism may be attributed to the construction of double Z-scheme heterojunction, photogenerated electron transfer and ROS generation through the redox cycle of Cu2+/Cu+ and Bi5+/Bi3+.