Photocatalytic Activation of Peroxymonosulfate by Bi4O5Br2 for Highly Efficient Atrazine Degradation

Using bismuth oxyhalides (BiOX) for the peroxymonosulfate (PMS)-assisted visible-light photocatalytic degradation of organic pollutants is a promising and environmentally friendly approach. However, pristine BiOBr suffers from limited visible-light absorption and low charge carrier mobility. In this study, Bi4O5Br2 microspheres were successfully synthesized and employed as a photocatalyst to activate PMS under visible light for the degradation of the herbicide atrazine (ATZ). Experimental results demonstrated that Bi4O5Br2 displayed markedly enhanced photocatalytic activation performance relative to pristine BiOBr, exhibiting a 9.15-fold increase in the apparent reaction rate constant for ATZ degradation. In addition, radical quenching experiments confirmed that singlet oxygen (1O2) and sulfate radicals (•SO4–) served as the primary reactive species. Furthermore, assessment using the Toxicity Estimation Software Tool (T.E.S.T) confirmed a significant reduction in the ecological toxicity of the degraded ATZ solution. This work not only presents an efficient photocatalytic-PMS synergistic degradation system but also offers a promising solution for the efficient removal of recalcitrant organic pollutants.