A Novel Persulfate Activation Strategy by Double Z-Scheme Bi2o3/Cubi2o4/Biobr Heterojunction: Non-Radical Dominated Pathway for Levofloxacin Degradation

Abstract

Persulfate oxidation technology is known as a novel wastewater treatment method due to its high tolerance to water environmental matrices. In the PMS activation process by bismuth-based semiconductors, in addition to conventional radicals ([[EQUATION]],·OH), non-radicals (1O2) can also be produced. Considering the poor self-stability of Bi2O3/CuBi2O4, we synthesized Bi2O3/CuBi2O4/BiOBr ternary composite material. For the effective elimination of levofloxacin, the non-radical pathway-dominated PMS activation was established. The results indicated that BiOBr not only provided abundant active sites for Bi2O3/CuBi2O4 but also promoted electron migration on the material surface. The composite material exhibited excellent catalytic performance (86.83% within 100 min), significantly higher than Bi2O3/CuBi2O4 (63.19%) and BiOBr (60.35%), [[EQUATION]] and 1O2 were the main active species. In order to efficiently enhance the transfer of photogenerated electrons and realize the generation of ROS,double Z-scheme heterojunction and redox cycles of Cu2+/Cu+ and Bi5+/Bi3+ were employed. This presented a novel research technique for treatment of organic-polluted water in the future.

Keywords: persulfate (PMS), BiOBr, Non-radical pathway, singlet oxygen (1O2)