Fig. 3

Characteristics of FP NPs. a The ability of O₂ generation in the different concentrations of H₂O₂ for α-Fe₂O₃ and FP. b The UV–vis spectra of time-dependent DPBF degradation after incubated with FP under US irradiation (1.0 MHz, 1.0 W cm⁻²). c The absorption of DPBF after incubated with α -Fe₂O₃, FP, FP + H₂O₂ under US irradiation. d Time-dependent fluorescence intensities of SOSG after incubated with FP and FP + H₂O₂ under US irradiation. e Solid UV–vis spectra of α-Fe₂O₃ and FP. f Nyquist plots of α-Fe₂O₃ and FP obtained from EIS measurements. g Schematic illustration for the function mechanisms of FP NPs