Boosting Reactive Oxygen Species Generation Over Bi3o4br/Cubi2o4 by Activating Peroxymonosulfate Under Visible Light Irradiation

Given the limitations of conventional advanced oxidation processes (AOPs), a coupling system by integrating sulfate radical-based AOPs (•SO4--AOPs) with photocatalysis for boosting the peroxymonosulfate (PMS) activation under visible light was established. Herein, we developed a novel 5%Bi3O4Br/CuBi2O4 catalyst for rapid and efficient degradation of tetracycline (TC). The rate constant (k) for degrading TC in 5%Bi3O4Br/CuBi2O4+PMS+Vis system was 3.69 min-1, which is 30.62, 2.18 times higher than that of photocatalysis and •SO4--AOPs alone, respectively. The quenching experiments verified that h+, •OH, •O2- and 1O2 were dominant contributors for the degradation of TC. EPR and quantitative analysis further implied illumination was favor in achieving mass production of •OH and 1O2. Moreover, •O2- and •SO4- might convert into 1O2 in the 5%Bi3O4Br/CuBi2O4+PMS+Vis system. The degradation pathways of TC were proposed and the toxicity of intermediates was much lower than that of untreated TC. Besides, the 5%Bi3O4Br/CuBi2O4+PMS+Vis system showed over 90% removal rate in a wide pH range (3-11) or different concentrations of inorganic anions. This work provided a worthy reference in developing an environmentally-friendly system for the high-efficiency degradation of antibiotics