The effect of oxygen in the photocatalytic oxidation pathways of perfluorooctanoic acid

Sansotera, Maurizio; Persico, Federico; Rizzi, V.; Panzeri, Walter; Pirola, Carlo; Bianchi, Claudia L.; Navarrini, W.

doi:10.1016/j.jfluchem.2015.06.019

Cited by 35 publications

(16 citation statements)

References 65 publications

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“…: light intensity (0.45-9.5 mW.cm -2 ), wavelength spectrum emitted by the light source (200-600 nm), reactor volume (0.12-3 L) and treatment time. The reaction medium has been also widely varied, in terms of PFOA concentration, background electrolytes and O2 or N2 supply [34]. Yet, the catalyst dosage was quite homogeneous in all the reviewed research, and was varied in the range of 0.25-2 g.L -1 .…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Photocatalytic degradation and mineralization of perfluorooctanoic acid (PFOA) using a composite TiO2 −rGO catalyst

Gómez-Ruiz

Ribao

Diban

et al. 2018

Journal of Hazardous Materials

180

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The inherent resistance of perfluoroalkyl substances (PFASs) to biological degradation makes necessary to develop advanced technologies for the abatement of this group of hazardous substances. The present work investigated the photocatalytic decomposition of perfluorooctanoic acid (PFOA) using a composite catalyst based on TiO and reduced graphene oxide (95% TiO/5% rGO) that was synthesized using a facile hydrothermal method. The efficient photoactivity of the TiO-rGO (0.1gL) composite was confirmed for PFOA (0.24mmolL) degradation that reached 93±7% after 12h of UV-vis irradiation using a medium pressure mercury lamp, a great improvement compared to the TiO photocatalysis (24±11% PFOA removal) and direct photolysis (58±9%). These findings indicate that rGO provided the suited properties of TiO-rGO, possibly as a result of acting as electron acceptor and avoiding the high recombination electron/hole pairs. The release of fluoride and the formation of shorter-chain perfluorocarboxilyc acids, that were progressively eliminated in a good match with the analysed reduction of total organic carbon, is consistent with a step-by-step PFOA decomposition via photogenerated hydroxyl radicals. Finally, the apparent first order rate constants of the TiO-rGO UV-vis PFOA decompositions, and the intermediate perfluorcarboxylic acids were found to increase as the length of the carbon chain was shorter.

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Section: Accepted Manuscriptmentioning

confidence: 99%

Photocatalytic degradation and mineralization of perfluorooctanoic acid (PFOA) using a composite TiO2 −rGO catalyst

Gómez-Ruiz

Ribao

Diban

et al. 2018

Journal of Hazardous Materials

180

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“…6). 85 The basic steps for shortening the chain (C n → C n−1 ) via photo-redox pathways were described in Eqns (1)- (9). Generally, the photocatalytic reaction was initiated with the excitation of TiO 2 -based photocatalysts, which was caused by light irradiation (Eqn (1)).…”

Section: Elucidating Of Mechanism For Degradation Of Perfluorocarboxymentioning

confidence: 99%

“…The proposed mechanism of perfluorooctanoic acid (PFOA) photodegradation over titanium dioxide (TiO 2 ) photocatalyst via two pathways: (A) photo-redox, and (B) ⊎-scission. Adapted with permission from Sansotera et al, 85 License No: 4718731463636.…”

Section: Elucidating Of Mechanism For Degradation Of Perfluorocarboxymentioning

confidence: 99%

Tailoring photocatalysts and elucidating mechanisms of photocatalytic degradation of perfluorocarboxylic acids (PFCAs) in water: a comparative overview

Thi

Nguyen

et al. 2020

J of Chemical Tech & Biotech

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A perfluorooctanoic acid (PFOA), as the most important representative of perfluorocarboxylic acids (PFCAs), is environmentally persistent and bioaccumulative. Among treatment techniques for PFOA decomposition, photocatalytic degradation of PFOA has received considerable attention. A series of candidate photocatalytic materials, including TiO2‐, carbonaceous‐, Ga2O3‐, In2O3‐based, etc., have been successfully proposed to eliminate PFOA. Overall, there are two types of mechanisms for photocatalytic degradation of PFCAs, including conventional mechanism and charge transfer mechanism. For a conventional mechanism, the mechanism of PFOA photodegradation over bulk TiO2 via two pathways: photo‐redox and β‐scission. For the charge transfer mechanism, the PFOA degradation pathway in water‐soluble H3PW12O40 is mainly via charge‐transfer excited complex ([PW12O40]3−*). Finally, attention on critical challenges and prospects for photodegradation of PFOA are also intensified. © 2020 Society of Chemical Industry

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“…Previous studies [6,12,15,19,20,41] been reached yet although many different theories such as the photo-redox or the β-scission pathway have been suggested [15]. Many factors can influence the proposed reaction pathway such as pH of the solution that can alter the behaviour of the PFOA.…”

Section: 2 Photocatalytic Degradation Of Pfoamentioning

confidence: 99%

“…Due to this characteristics PFOA has been widely utilized in industrial and commercial applications in the past six decades ranging from coatings for clothing, leather and carpets that are water, soil and stain resistant; oil resistant coatings for food packages; aviation hydraulic fluids; fire retardants (fire-fighting foams) until industrial utilization as surfactants; emulsifiers; wetting agents; additives and coatings for production of polytetrafluorethylene (PTFE) and others [8][9][10][11][12]. The same characteristics that makes it an important industrial and commercial constituent also makes PFOA a strong bioaccumulative and persistent compound and therefore it has often been found in the environment around the world, mainly in the water matrix, such as finished drinking water, surface water and groundwater, but also in sludge, soils, sediments, outdoor and indoor dust, polar ice caps and recently also in living organisms [8,[13][14][15]. The presence of PFOA in the environment is due to human activities, since it is an anthropogenic compound, and it can be either directly or indirectly released into the environment [16].…”

Section: Introductionmentioning

confidence: 99%

Photocatalytic Degradation of Perfluorooctanoic Acid (PFOA) From Wastewaters by TiO2, In2O3 and Ga2O3 Catalysts

et al. 2017

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14The aim of the work was to prepare nanosized In2O3 and Ga2O3 photocatalysts for degradation of 15Perfluorooctanoic acid (PFOA) in water. Their commercial references along with TiO2 were used as 16 a comparison basis. The characterization of the materials proved that successful preparation of cubic 17In2O3 and monoclinic ß-Ga2O3 were achieved via solvothermal and hydrothermal methods, 18 respectively. The effect of different parameters such as catalyst dosage, UV light source and 19 utilization of inorganic oxidant in PFOA treatment were evaluated. In2O3, photocatalyst was the most 20 efficient in the degradation of 15 mgL -1 PFOA under UVB irradiation and synthetic air reaching 27% 21 of degradation, which was 20 percentage points higher than for commercial In2O3. This is proposed 22 to be partly due to significantly higher specific surface area of the self-made In2O3 and smaller 23 crystallite size and partly due to more efficient absorption of UVB light compared to the other tested 24 materials. Addition of KBrO3 did not improve the activity of self-made In2O3.

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The effect of oxygen in the photocatalytic oxidation pathways of perfluorooctanoic acid

Cited by 35 publications

References 65 publications

Photocatalytic degradation and mineralization of perfluorooctanoic acid (PFOA) using a composite TiO2 −rGO catalyst

Photocatalytic degradation and mineralization of perfluorooctanoic acid (PFOA) using a composite TiO2 −rGO catalyst

Tailoring photocatalysts and elucidating mechanisms of photocatalytic degradation of perfluorocarboxylic acids (PFCAs) in water: a comparative overview

Photocatalytic Degradation of Perfluorooctanoic Acid (PFOA) From Wastewaters by TiO2, In2O3 and Ga2O3 Catalysts

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