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Wojnárovits L, Takács E. Rate constants of dichloride radical anion reactions with molecules of environmental interest in aqueous solution: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:41552-41575. [PMID: 34086177 PMCID: PMC8354983 DOI: 10.1007/s11356-021-14453-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/13/2021] [Indexed: 05/14/2023]
Abstract
Natural waters, water droplets in the air at coastal regions and wastewaters usually contain chloride ions (Cl-) in relatively high concentrations in the milimolar range. In the reactions of highly oxidizing radicals (e.g., •OH, •NO3, or SO4•-) in the nature or during wastewater treatment in advanced oxidation processes the chloride ions easily transform to chlorine containing radicals, such as Cl•, Cl2•-, and ClO•. This transformation basically affects the degradation of organic molecules. In this review about 400 rate constants of the dichloride radical anion (Cl2•-) with about 300 organic molecules is discussed together with the reaction mechanisms. The reactions with phenols, anilines, sulfur compounds (with sulfur atom in lower oxidation state), and molecules with conjugated electron systems are suggested to take place with electron transfer mechanism. The rate constant is high (107-109 M-1 s-1) when the reduction potential the one-electron oxidized species/molecule couple is well below that of the Cl2•-/2Cl- couple.
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Affiliation(s)
- László Wojnárovits
- Radiation Chemistry Department, Institute for Energy Security and Environmental Safety, Centre for Energy Research, H-1121 Konkoly-Thege Miklós út, Budapest, 29-33, Hungary
| | - Erzsébet Takács
- Radiation Chemistry Department, Institute for Energy Security and Environmental Safety, Centre for Energy Research, H-1121 Konkoly-Thege Miklós út, Budapest, 29-33, Hungary.
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Lanzalunga O, Lapi A. Recent photo- and radiation chemical studies of sulfur radical cations. J Sulphur Chem 2011. [DOI: 10.1080/17415993.2011.619536] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Osvaldo Lanzalunga
- a Dipartimento di Chimica and IMC-CNR, Sezione Meccanismi di Reazione , Università “La Sapienza” , P.le A. Moro, 5 I-00185 , Rome , Italy
| | - Andrea Lapi
- a Dipartimento di Chimica and IMC-CNR, Sezione Meccanismi di Reazione , Università “La Sapienza” , P.le A. Moro, 5 I-00185 , Rome , Italy
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Tachikawa T, Tojo S, Fujitsuka M, Majima T. One-Electron Oxidation Pathways during β-Cyclodextrin-Modified TiO2 Photocatalytic Reactions. Chemistry 2006; 12:7585-94. [PMID: 16927273 DOI: 10.1002/chem.200600097] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The photocatalytic one-electron oxidation reactions of aromatic sulfides using the carboxymethyl-beta-cyclodextrin (CM-beta-CD)-modified TiO(2) nanoparticles (TiO(2)/CM-beta-CD) were investigated by using nano- and femtosecond transient absorption spectroscopies. The one-electron oxidation processes of the substrate (S) by the valence band hole (h(VB) (+)) at the TiO(2) surface and the trapped hole at the adsorption site of the CM-beta-CD (h(CD) (+)) were examined. The transient absorption spectra and time traces observed for the charge carriers and the radical cation of S (S(.+)) revealed that the one-electron oxidation reaction of S during the nano- and femtosecond laser flash photolyses of TiO(2)/CM-beta-CD is significantly enhanced relative to bare TiO(2). The kinetics of the decay and the dimerization processes between S(.+)s are discussed on the basis of the results obtained by the pulse radiolysis technique.
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Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN) Osaka University Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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Tachikawa T, Tojo S, Fujitsuka M, Majima T. One-Electron Redox Processes during Polyoxometalate-Mediated Photocatalytic Reactions of TiO2 Studied by Two-Color Two-Laser Flash Photolysis. Chemistry 2006; 12:3124-31. [PMID: 16358350 DOI: 10.1002/chem.200501077] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The one-electron redox processes of several compounds during polyoxometalate (POM)-mediated photocatalytic reactions of TiO(2) were investigated using the two-color two-laser flash-photolysis technique. The efficiency of the one-electron oxidation of aromatic sulfides by the trapped hole (h(tr) (+)) or the surface-bound OH radical (OH(s) (.)) is found to be significantly enhanced due to electron transfer from the conduction band (CB) of TiO(2) to the POM. The efficiency of the electron transfer from the CB of TiO(2) to the POM decreases in the order H(2)W(12)O(40) (6-) < SiW(12)O(40) (4-) < PW(12)O(40) (3-), that is, it depends on the reduction potential (E(red)) of the POMs. Electron injection from PW(12)O(40) (4-) in the excited state (PW(12)O(40) (4-*)) to the CB of TiO(2) was clearly observed using the two-color two-laser flash-photolysis technique. Storage of electrons in the TiO(2)/PW(12)O(40) (3-)/methyl viologen (MV(2+)) ternary system was also achieved upon two-color two-laser irradiation.
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Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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Tachikawa T, Tojo S, Fujitsuka M, Majima T. Exclusion of Aromatic Radical Cations from Cyclodextrin Nanocavity Studied by Pulse Radiolysis. J Phys Chem B 2005; 109:17460-6. [PMID: 16853232 DOI: 10.1021/jp0528663] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The influence of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the one-electron oxidation reaction of aromatic sulfides (S) with Br2*- and the decay process of the S radical cation (S*+) was investigated by pulse radiolysis. The dissociation kinetics of S*+ from the CD cavity was examined in terms of the apparent equilibrium constants (Kapp) for the formation and decay processes of S*+. Inhibition of the one-electron oxidation reaction of S by Br2*- was clearly observed in the presence of HP-beta-CD. On the basis of a comparison between the determined Kapp values, it was found that the binding ability of S*+ with HP-beta-CD is much lower than that of S, because of the hydrophobic nature of the cavity. The formation process of the dimer radical cation of 4-(methylthio)phenylmethanol ((MTPM)2*+), which is generated between MTPM(*+) and neutral MTPM in solution, was also inhibited by the addition of HP-beta-CD.
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Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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Tachikawa T, Tojo S, Kawai K, Endo M, Fujitsuka M, Ohno T, Nishijima K, Miyamoto Z, Majima T. Photocatalytic Oxidation Reactivity of Holes in the Sulfur- and Carbon-Doped TiO2 Powders Studied by Time-Resolved Diffuse Reflectance Spectroscopy. J Phys Chem B 2004. [DOI: 10.1021/jp0470593] [Citation(s) in RCA: 235] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Sachiko Tojo
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Kiyohiko Kawai
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Masayuki Endo
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Teruhisa Ohno
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Kazumoto Nishijima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Zenta Miyamoto
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan, and Department of Applied Chemistry, Faculty of Engineering, Kyushu Institute of Technology, Sensuicho 1-1, Tobata, Kitakyushu 804-8550, Japan
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Tachikawa T, Tojo S, Fujitsuka M, Majima T. Influences of Adsorption on TiO2 Photocatalytic One-Electron Oxidation of Aromatic Sulfides Studied by Time-Resolved Diffuse Reflectance Spectroscopy. J Phys Chem B 2004. [DOI: 10.1021/jp037003t] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Sachiko Tojo
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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