Revisiting the Role of Peroxymonosulfate in TiO2-Mediated Photocatalytic Oxidation: Dependence of Kinetic Enhancement on Target Substrate and Surface Platinization

Moonkyu Kim, Jaesung Kim, Hae In Cho, Eun Tae Yun, Jaemin Choi, Minjeong Kim, Hongshin Lee, Min Cho, Hyoung Il Kim, Jaesang Lee

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

An enhancing effect of peroxymonosulfate (PMS) on photocatalytic activity has previously been demonstrated, but the research focus was concentrated primarily on the extent to which treatment efficiency was improved. To further comprehend the role of PMS, this study examined the TiO2 photocatalytic systems in the presence of PMS for the oxidation of diverse organics and showed that the extent of performance enhancement via PMS addition was substrate-dependent. This resulted from the involvement of multiple oxidants owing to the dual role of PMS as an electron acceptor and a radical precursor, confirmed in the open circuit potential shifts and electron paramagnetic resonance spectra. Surface platinization, typically adopted to modulate charge carrier dynamics in photocatalysis, caused the nonphoton-driven degradative pathway, i.e., mediated electron transfer involving PMS as a two-electron acceptor, and promoted the one-electron reduction of PMS to sulfate radicals (SO4•-). The contribution of SO4•- was assessed based on efficiencies for decarboxylation and hydroxylation, isomer distribution in the hydroxylated intermediates, the quenching effect of alcohols, and net conversion of methanol to formaldehyde. Relying on the selective reactivity of Pt-activated PMS, Pt-TiO2/PMS outperformed bare TiO2/PMS in oxidatively treating the binary mixtures of organics and enabled effective organic degradation under periodic light irradiation.

Original languageEnglish
Pages (from-to)1530-1541
Number of pages12
JournalACS ES and T Engineering
Volume1
Issue number11
DOIs
Publication statusPublished - 2021 Nov 12

Bibliographical note

Publisher Copyright:
© 2021 American Chemical Society.

Keywords

  • peroxymonosulfate
  • photocatalysis
  • substrate-specificity
  • sulfate radical
  • surface platinization

ASJC Scopus subject areas

  • Chemical Engineering (miscellaneous)
  • Environmental Chemistry
  • Process Chemistry and Technology
  • Chemical Health and Safety

Fingerprint

Dive into the research topics of 'Revisiting the Role of Peroxymonosulfate in TiO2-Mediated Photocatalytic Oxidation: Dependence of Kinetic Enhancement on Target Substrate and Surface Platinization'. Together they form a unique fingerprint.

Cite this