Catalyst-Free Photochemical Activation of Peroxymonosulfate in Xanthene-Rich Systems for Fenton-Like Synergistic Decontamination: Efficacy of Proton Transfer Process

Catalyst-free visible light assisted Fenton-like catalysis offers opportunities to achieve the sustainable water decontamination, but the synergistic decontamination mechanisms are still unclear, especially the effect of proton transfer process (PTP). The conversion of peroxymonosulfate (PMS) in photosensitive dye-enriched system was detailed. The photo-electron transfer between excited dye and PMS triggered the efficient activation of PMS and enhanced the production of reactive species. Photochemistry behavior analysis and DFT calculations revealed that PTP was the crucial factor to determine the decontamination performance, leading to the transformation of dye molecules. The excitation process inducing activation of whole system was composed of low energy excitations, and the electrons and holes were almost contributed by LUMO and HOMO. This work provided new ideas for the design of catalyst-free sustainable system for efficient decontamination.

Automated summary

Catalyst-free visible light assisted Fenton-like catalysis provides opportunities for sustainable water decontamination, but the synergistic decontamination mechanisms, especially the effect of proton transfer process (PTP), are still unclear. This study detailed the conversion of peroxymonosulfate (PMS) in a photosensitive dye-enriched system. The photo-electron transfer between the excited dye and PMS triggered efficient activation of PMS and enhanced the production of reactive species. Photochemistry behavior analysis and DFT calculations revealed that PTP was the crucial factor determining the decontamination performance by transforming dye molecules, and the excitation process involved low energy excitations, with electrons and holes mainly contributed by LUMO and HOMO.