Fig. 4: CAT-mimicking performance and mechanism investigation of Fe₁/NC SACs.

a Time-dependent O₂ generation in Britton–Robison (BR) buffer containing 5 mM H₂O₂ and 5 μg·mL⁻¹ catalysts. b Specific activities (SA, U·mg⁻¹) of Fe₁/NC SACs in BR buffer (pH 7.0) containing 5 mM H₂O₂. c Kinetics for CAT-like activity of Fe₁/NC SACs (5 μg·mL⁻¹) with different concentrations of H₂O₂. EPR spectra of 25 mM BMPO in methanol containing 5 mM H₂O₂ without or with 5 μg·mL⁻¹ Fe₁/NC-800 (d), Fe₁/NC-900 (e), Fe₁/NC-1000 (f) and their controls. Blank: no catalyst. g Schematic structure of Fe₁/NC-900 with intermediates during the catalytic H₂O₂ disproportionation reaction. N, blue; C, gray; O, red; H, light gray; Fe, deep red. h Free energy diagrams of H₂O₂ disproportionation on Fe₁/NC SAzymes. Each experiment was repeated independently three times with similar results (a–f). Representative plots are shown. Source data are provided with the paper.