Fig. 3.

Reactive intermediates identification. (A) ESR spectra of different systems using DMPO and TEMP as trapping agents. (B) UHPLC/MS chromatogram of the typical DPAO₂ from the oxidation of DPA in Fe₂O₃@FCNT-H/H₂O₂ system. Reaction conditions: pH = 5.0, T = 293.2 K, [Fe₂O₃@FCNT-H] = 1.5 × 10⁻² g∙L⁻¹, [H₂O₂] = 50 mM, [DMPO] = [TEMP] = 50 mM for A, and [DPA] = 10 μM, [ACN] = 50 mM, reaction time = 60 min for B.