The role of dissolved oxygen in the Ta(O)N-driven visible Fenton-like degradation of atrazine

•DO suppressed atrazine degradation in the visible-Ta(O)N–Fenton-like system.•Atrazine degradation was based on •OH attack in visible-Ta(O)N–Fenton-like system.•Product from DO, i.e., O2•− is not the effective oxidant for atrazine degradation.•The presence of DO slowed down the photoreduction of Fe3+.•The presence of DO had no obvious effect on H2O2 decomposition.

The role of dissolved oxygen (DO) in a visible Fenton-like degradation of atrazine driven by Ta(O)N was examined in detail. First, Ta(O)N samples were prepared by the nitridation of Ta2O5 nanoparticles, which showed strong absorption in the range of 300–600 nm. Second, the degradation of atrazine, the decomposition of H2O2, and the formation of intermediates in the visible Ta(O)N-Fenton-like system in the presence of DO were compared with those in the absence of DO. In the visible Ta(O)N–Fenton-like system, atrazine degradation was based on the attack of •OH and the atrazine degradation pathways were similar in the presence and absence of DO. Notably, however, the presence of DO suppressed atrazine degradation. An investigation into the effects of DO on the photoreduction of Fe3+ and the photodecomposition of H2O2 catalyzed by Ta(O)N showed that the presence of DO suppressed the formation of Fe2+ but did not affect the decomposition of H2O2. Therefore, the presence of DO slowed the generation of •OH. The role of DO in atrazine degradation by a visible Ta(O)N-Fenton-like system was proposed on the basis of the experimental results.

Graphical abstractRoles of dissolved oxygen in the visible-Fenton-like degradation of atrazine.Figure optionsDownload full-size imageDownload as PowerPoint slide