Fig. 4. Fenton-like reaction-catalyzed ability of As/As_xO_y NSs.

a Degradation of MB caused by the generation of ·OH with different concentration of As/As_xO_y NSs (5–15 μg/mL). b ESR spectra of ·OH generated by As/As_xO_y NSs. c O₂ generation by As/As_xO_y NSs at different concentrations (5–15 μg/mL). d The mechanism of As/As_xO_y NSs for generation of ·OH and O₂. As^III with high reducibility catalyzes the disproportionate reaction of H₂O₂ to generate ·OH, and As^V with high oxidizability catalyzes the oxidation of H₂O₂ to generate O₂ and realizes regeneration of As^III. Three times each experiment was repeated independently with similar results.