Decatungstate photocatalysis

Taniélian, Charles

doi:10.1016/s0010-8545(98)00160-x

Cited by 192 publications

(150 citation statements)

References 49 publications

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“…This suggests that for the degradation mechanism of KGN with HPA, there may exist another degradation mechanism besides the mechanism wherein OH radicals attack. Some studies have reported that HPA can directly photocatalytically degrade the pollutants by abstracting H atom from the pollutants [28][29][30][31][32]. Based on the above results, it is plausible that there is a synergistic effect between the oxidation of • OH and the direct photocatalysis of KGN with H 3 PW 12 O 40 .…”

Section: Anion Products Investigation During Photocatalytic Oxidationmentioning

confidence: 88%

RETRACTED ARTICLE: Kinetic and anion degradation products study on photocatalytic degradation of reactive orange 5 solution with phosphotungstic acid

Zhong

Zhao

et al. 2008

Open Chemistry

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Increasing environmental pollution caused by toxic dyes is a matter of great concern due to their hazardous nature. So it is crucial to develop processes which can destroy these dyes effectively. It has been generally agreed that reactive orange 5 (KGN) can be effectively degraded in aerated phosphotungstic acid (HPA) in a homogeneous reaction system using near-UV irradiation. In this paper, photocatalytic degradation of reactive orange 5 solutions with phosphotungstic acid was investigated, especially more attention was paid to the kinetic model and the anion degradation products. The results revealed that the photocatalytic degradation reaction of KGN with HPA in a homogenous solution can be described by Langmuir-Hinshelwood equation and Langmuir-Hinshewood kinetic model described it well. The reaction manifested the first order with lower concentration(≤30 mg L , respectively. The degradation mechanism of KGN with HPA is different from that with TiO 2 , the anion products of the two reaction systems are the same. The difference in degradation mechanism of KGN with HPA from that with TiO 2 is caused by the nature of the photocatalyst. Warsaw and Springer-Verlag Berlin Heidelberg. © Versita

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Section: Anion Products Investigation During Photocatalytic Oxidationmentioning

confidence: 88%

RETRACTED ARTICLE: Kinetic and anion degradation products study on photocatalytic degradation of reactive orange 5 solution with phosphotungstic acid

Zhong

Zhao

et al. 2008

Open Chemistry

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“…Furthermore, the activity of polyoxotungstates in promoting photocatalytic oxygenation of organic substrates is documented, both in organic solvents and in aqueous-phase [14,15]. In particular, the photocatalytic properties of the decatungstate anion W 10 O 32 4) have been extensively studied in acetonitrile solution [16][17][18][19][20] and applied also to photooxygenation in water [19,21,22]. Its Uv-Vis spectrum (Scheme 1) shows a maximum absorption band at 324 nm, which overlaps with the UV solar emission, so opening the potential for environmentally benign solarphotoassisted applications [19].…”

Section: Introductionmentioning

confidence: 99%

“…The main drawback of POM-based photocatalysis lies in the low quantum yields (in the range 0.1-0.5) [17,18], associated to a limited absorption in the most desirable visible range (Scheme 1). Because of this, high photocatalyst/substrate ratios are generally required to elicit fast and efficient oxygenation cycles.…”

Section: Introductionmentioning

confidence: 99%

Hybrid photocatalytic membranes embedding decatungstate for heterogeneous photooxygenation

et al. 2006

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The incorporation of decatungstate in polymeric membranes provides new heterogeneous photocatalysts for the oxidation of organic substrates under oxygen atmosphere at 25°C. Photocatalytic membranes have been prepared yielding polymeric films with a high thermal, chemical and mechanical stability (PVDF, PDMS, Hyflon). Surface spectroscopy techniques including transmittance and reflectance UV-Vis and FT-IR have been used to assess the photocatalyst integrity within the polymeric support. Catalyst screening has been performed under both homogeneous and heterogeneous photooxygenation conditions. The photocatalyst activity has been evaluated in terms of the substrate conversion, turnover numbers, and recycling experiments. A membrane induced selectivity behavior has been evidenced by comparison with homogeneous oxidations.

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“…[2,20,24,27] Furthermore, the solvent effect on the lifetime of the photoactive transient and on the oxidation rates of different substrates appears complicated, which hampers a direct comparison of the kinetic results obtained in different media. [23,24] Basically, two main drawbacks dictate the method×s limitation especially for practical organic synthesis: these are (i) low quantum yields, which are generally found in the range 0.1 ± 0.5, [22,23] (ii) poor selectivity, due to fast over-oxidation processes leading eventually to substrate mineralisation. [2,3] Both issues can be addressed through the heterogenisation of the photocatalyst, which may allow a significant increase of the total turnover number (TON) by catalyst recycling and a selectivity tuning as a function of the substrate affinity towards the heterogeneous support.…”

Section: Introductionmentioning

confidence: 99%

Heterogeneous Photooxidation of Alcohols in Water by Photocatalytic Membranes Incorporating Decatungstate

et al. 2003

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The incorporation of decatungstate in polymeric membranes provides new heterogeneous photocatalysts for the oxidation of organic substrates performed in water under an oxygen atmosphere at 25 8C. The photooxidation of water-soluble alcohols proceeds to completion, forming the carbonyl derivative as an intermediate, and leading to degradation products with a COD loss up to 70%. Solid state characterisation techniques (SEM, IR) together with solution UV-VIS analysis and kinetic studies allowed us to identify, among diverse polymeric materials, the PDMS-based system as leaching-free under irradiation and recyclable up to >300 turnovers (4 runs) with no major loss of activity. Membrane induced discrimination of the substrate results from the oxidations of a series of alcohols, through comparison with the homogeneous reactions.

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Decatungstate photocatalysis

Cited by 192 publications

References 49 publications

RETRACTED ARTICLE: Kinetic and anion degradation products study on photocatalytic degradation of reactive orange 5 solution with phosphotungstic acid

RETRACTED ARTICLE: Kinetic and anion degradation products study on photocatalytic degradation of reactive orange 5 solution with phosphotungstic acid

Hybrid photocatalytic membranes embedding decatungstate for heterogeneous photooxygenation

Heterogeneous Photooxidation of Alcohols in Water by Photocatalytic Membranes Incorporating Decatungstate

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