Insight into the activation of persulfate with Cu2O/visible-light: Cu(I) based photo-Fenton and Cu2O surface mediated free radical mechanism

In this research, persulfate (PS) was applied to enhance the photo-excited charge separation of Cu2O, which could simultaneously promote the activation of persulfate for wastewater decontamination. The results showed that Cu2O/PS/visible-light system exhibited excellent degradation performance. Cu(I) based photo-Fenton was demonstrated that Cu(I) in aqueous media could effectively activate PS and recycled by the photo-reduction. Besides, Cu2O surface mediated free radical mechanism was proposed that the metastable surface mediated SO4•- and O2•- were more active than that in aqueous media. Both homogeneous and.heterogeneous activation process towards PS were accountable for the generating of active free radicals. This work not only provides a facile effective photocatalytic system for removing contaminants, but also gives further insights about the complicated mechanisms of semiconductor-based photocatalytic activation of PS.