Abstract
Fullerenes and their derivatives are known to photosensitize the production of singlet oxygen (1O2), but their role in generating hydroxyl radical (•OH) under visible light has not been reported. Here, we demonstrate that fullerol can mediate the electron transfer from Rhodamine B dye to O2 under visible light irradiation, achieving simultaneous dye decolorization and •OH-induced degradation of 4-chlorophenol. The hydroxyl radical is proposed to be produced via a consecutive reduction of molecular oxygen by fullerol anion radical, which is formed through the electron transfer from the dye to the triplet state of fullerol. Mechanistic investigations using various probe reagents such as superoxide dismutase (superoxide quencher), t-butanol (•OH quencher), and coumarin (•OH probe) provided indirect evidence for the generation of •OH under visible light. Furthermore, spin trapping technique directly detected the oxidizing species such as 1O2 in the visible light irradiated solution of RhB/fullerol mixture. It was proposed that the photochemical oxidation mechanism depends on pH: production is favored at acidic pH through fullerol-mediated sequential electron transfer while 1O2 is generated as a main oxidant at neutral and alkaline condition through the energy-transfer process. Therefore, the photochemical oxidation can be switchable between •OH-driven and 1O2-driven mechanism by a simple pH adjustment.
| Original language | English |
|---|---|
| Pages (from-to) | 10545-10553 |
| Number of pages | 9 |
| Journal | Environmental Science and Technology |
| Volume | 50 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - 2016 Oct 4 |
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ASJC Scopus subject areas
- Chemistry(all)
- Environmental Chemistry
Cite this
Visible Light Sensitized Production of Hydroxyl Radicals Using Fullerol as an Electron-Transfer Mediator. / Lim, Jonghun; Kim, Hyejin; Alvarez, Pedro J J; Lee, Jaesang; Choi, Wonyong.
In: Environmental Science and Technology, Vol. 50, No. 19, 04.10.2016, p. 10545-10553.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Visible Light Sensitized Production of Hydroxyl Radicals Using Fullerol as an Electron-Transfer Mediator
AU - Lim, Jonghun
AU - Kim, Hyejin
AU - Alvarez, Pedro J J
AU - Lee, Jaesang
AU - Choi, Wonyong
PY - 2016/10/4
Y1 - 2016/10/4
N2 - Fullerenes and their derivatives are known to photosensitize the production of singlet oxygen (1O2), but their role in generating hydroxyl radical (•OH) under visible light has not been reported. Here, we demonstrate that fullerol can mediate the electron transfer from Rhodamine B dye to O2 under visible light irradiation, achieving simultaneous dye decolorization and •OH-induced degradation of 4-chlorophenol. The hydroxyl radical is proposed to be produced via a consecutive reduction of molecular oxygen by fullerol anion radical, which is formed through the electron transfer from the dye to the triplet state of fullerol. Mechanistic investigations using various probe reagents such as superoxide dismutase (superoxide quencher), t-butanol (•OH quencher), and coumarin (•OH probe) provided indirect evidence for the generation of •OH under visible light. Furthermore, spin trapping technique directly detected the oxidizing species such as 1O2 in the visible light irradiated solution of RhB/fullerol mixture. It was proposed that the photochemical oxidation mechanism depends on pH: production is favored at acidic pH through fullerol-mediated sequential electron transfer while 1O2 is generated as a main oxidant at neutral and alkaline condition through the energy-transfer process. Therefore, the photochemical oxidation can be switchable between •OH-driven and 1O2-driven mechanism by a simple pH adjustment.
AB - Fullerenes and their derivatives are known to photosensitize the production of singlet oxygen (1O2), but their role in generating hydroxyl radical (•OH) under visible light has not been reported. Here, we demonstrate that fullerol can mediate the electron transfer from Rhodamine B dye to O2 under visible light irradiation, achieving simultaneous dye decolorization and •OH-induced degradation of 4-chlorophenol. The hydroxyl radical is proposed to be produced via a consecutive reduction of molecular oxygen by fullerol anion radical, which is formed through the electron transfer from the dye to the triplet state of fullerol. Mechanistic investigations using various probe reagents such as superoxide dismutase (superoxide quencher), t-butanol (•OH quencher), and coumarin (•OH probe) provided indirect evidence for the generation of •OH under visible light. Furthermore, spin trapping technique directly detected the oxidizing species such as 1O2 in the visible light irradiated solution of RhB/fullerol mixture. It was proposed that the photochemical oxidation mechanism depends on pH: production is favored at acidic pH through fullerol-mediated sequential electron transfer while 1O2 is generated as a main oxidant at neutral and alkaline condition through the energy-transfer process. Therefore, the photochemical oxidation can be switchable between •OH-driven and 1O2-driven mechanism by a simple pH adjustment.
UR - http://www.scopus.com/inward/record.url?scp=84989947139&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84989947139&partnerID=8YFLogxK
U2 - 10.1021/acs.est.6b03250
DO - 10.1021/acs.est.6b03250
M3 - Article
C2 - 27588691
AN - SCOPUS:84989947139
VL - 50
SP - 10545
EP - 10553
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 19
ER -