Degradation of 4-chloro-2-methylphenol in aqueous solution by UV irradiation in the presence of titanium dioxide

Irmak, Sibel; Kuşvuran, Erdal; Erbatur, Oktay

doi:10.1016/j.apcatb.2004.06.003

Cited by 127 publications

(69 citation statements)

References 37 publications

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“…When HClO 4 is used, the degradation rate increases with perchlorate ion concentration which cancels the effect of pH observed with HCl. Similar results were obtained by IRMAK et al (2004) who showed that oxyhalogens such as IO 4 -, BrO 3 , ClO 3 -increase the degradation rate of organic pollutants by capturing the electrons ejected from TiO 2 so that the probability of recombination of e -/h + pairs will decrease. • At pH> 6.3, the degradation rate decreased with the increasing pH value beyond the pzc.…”

Section: Effect Of Initial Phsupporting

confidence: 74%

Photocatalytic Degradation of Monolinuron and Linuron in an Aqueous Suspension of Titanium Dioxide Under Simulated Solar Irradiation

Zouaghi

Zertal

David

et al. 2007

rseau

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The photocatalytic degradation of two phenylurea herbicides, monolinuron (MLN) and linuron (LN), was investigated in an aqueous suspension of TiO2 using simulated solar irradiation. The objective of the study was to compare their photocatalytic reactivity and to assess the influence of various parameters such as initial pesticide concentration, catalyst concentration and photonic flux on the photocatalytic degradation rate of MLN and LN. A comparative study of the photocatalytic degradation kinetics of both herbicides showed that these two compounds have a comparable reactivity with TiO2/simulated sun light. Under the operating conditions of this study, the photocatalytic degradation of MLN and LN followed pseudo first-order decay kinetics. The kobs values indicated an inverse dependence on the initial herbicide concentration and were fitted to the Langmuir-Hinshelwood equation. Photocatalytic degradation rates increased with TiO2 dosage, but overdoses did not necessarily increase the photocatalytic efficiency. The degradation rate of MLN increased with radiant flux until an optimum at 580 W m‑2 was reached and then decreased. Under these conditions, an electron-hole recombination was favored. Finally, the photocatalytic degradation rate depended on pH, where an optimum was found at a pH value close to the pH of the point of zero charge (pH = 6).La dégradation photocatalytique de deux herbicides, le monolinuron (MLN) et le linuron (LN), a été étudiée dans une suspension de TiO2 au contact de lumière solaire simulée. L’objectif de cette étude est de comparer leur photoréactivité et d’évaluer l’influence de différents paramètres tels que la concentration initiale en pesticide, la concentration en catalyseur et le flux photonique sur la cinétique de dégradation du monolinuron. L’étude comparative de la dégradation des deux herbicides a montré que les deux composés présentent une réactivité comparable avec le système TiO2/lumière simulée. Dans les conditions opératoires de cette étude, la dégradation photocatalytique du LN et du MLN suit une cinétique de pseudo ordre 1. La pseudo-constante kobs est inversement proportionnelle à la concentration initiale en pesticide et peut être décrite par une équation de Langmuir-Hinshelwood. L’étude de l’influence de la concentration en TiO2 a permis de montrer que la cinétique de dégradation du MLN augmente avec la dose de catalyseur, mais un surdosage n’est pas nécessaire pour augmenter l’efficacité du procédé. Cette étude a permis également de montrer que la pseudo‑constante d’ordre 1 de dégradation du MLN augmente linéairement avec le flux lumineux jusqu’à 580 W m-2 puis décroît. Dans ces conditions, la recombinaison des électrons trous est favorisée. Enfin, la cinétique de dégradation du MLN en fonction du pH passe par un optimum de pH proche du pH de point de charge nulle (pH = 6)

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Section: Effect Of Initial Phsupporting

confidence: 74%

Photocatalytic Degradation of Monolinuron and Linuron in an Aqueous Suspension of Titanium Dioxide Under Simulated Solar Irradiation

Zouaghi

Zertal

David

et al. 2007

rseau

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“…The particle of TiO 2 in the anatase phase has a mostly spherical morphology (Figure 5(a)). The area selected for electron diffraction pattern analysis (SAED) (Figure 5(b)), confirming that the TiO 2 -NiO nanoparticles are also highly crystalline in the anatase phase, rutile phase and TiNiO 3 .…”

Section: The Characteristics Of Tio 2 -Nio Filmmentioning

confidence: 76%

“…TiO 2 films were often prepared by using either sol-gel method [19]- [25], pray pyrolysis [26] or sputtering [27]. Metal oxides, such as CuO, Cu 2 O, Fe 2 O 3 , WO 3 , MoO 3 , ZnO, NiO, SnO 2 , and so on, have been considered for band-gap engineering of TiO 2 as these oxides have compatible processing strategies with TiO 2 [28]- [37]. Among these oxides, low band-gap CuO or NiO is used as sensitizers to use visible radiation, whereas other large band-gap oxides (e.g., ZnO, SnO 2 ) are coupled with TiO 2 for extrinsic trapping of photogenerated charge carriers to enhance photoactivity.…”

Section: Introductionmentioning

confidence: 99%

Visible Light Photoelectrocatalytic Degradation of Rhodamine B Using Ti/TiO2-NiO Photoanode

Wahyuningsih¹,

Purnawan²,

Saraswati³

et al. 2014

JEP

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The method of Ti/TiO 2 -NiO photoelectrode prepared by using sol-gel method continued by calcination process was introduced. The prepared TiO 2 -NiO film was observed with XRD and TEM. The anatase-rutile TiO 2 was mainly on the prepared TiO 2 -NiO composite surface electrode. In addition to NiO, the composite also formed NiTiO 3 that increased with increasing calcination temperature. Photoelectrocatalytic degradation of Rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. Through comparison of the photoelectrocatalytic oxidation using the Ti/TiO 2 -NiO electrode operated by single photoanode with the Ti/TiO 2 -NiO electrode operated by several photoanode, it was found that the photoelectrocatalytic efficiency of that by series photoanodes was higher. Additionally, photoelectrocatalytic system was performed at the several different photoelectrodes, which verified the higher photocatalytic activity compared with the single photoelectrode.

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“…Degradation levels could also be improved using various oxidants as electron scavengers. Such inorganic oxidants as IO 4 -, S 2 O 8 2-, BrO 3 -, ClO 3 -, and H 2 O 2 can be utilized as additives instead of oxygen to enhance the photodegradation rates of organic substrates by quenching the conduction band electrons and form reactive radical intermediates [5][6][7]. These oxidants increase the effectiveness of UV/photocatalyst in degrading organic substrates by capturing the electrons that are ejected from the photocatalyst, to reduce the probability of recombination of photogenerated electrons and photogenerated holes: the available number and survival time of the photogenerated holes is thus increased, promoting their effective reaction with organic substrates.…”

Section: Introductionmentioning

confidence: 99%

Decolorization of C.I. reactive red 198 in UV/oxidant and UV/TiO2/oxidant systems

2011

Reac Kinet Mech Cat

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In this study, UV/oxidant and UV/TiO 2 /oxidant systems were employed to treat textile wastewater. The parent compound was C.I. reactive red 198 (RR198). The selected oxidants were H 2 O 2 , Na 2 S 2 O 8 , NaBrO 3 , and NaIO 4 . The effects of oxidant dosage (1-24 mM), wavelength of UV (254 and 365 nm) and radical scavenger addition (C 2 H 5 OH) were determined in UV/oxidant systems. The experimental results revealed that all oxidants effectively decolorized RR198 under 254 nm irradiation; however, only Na 2 S 2 O 8 and NaIO 4 can decolorize RR198 under 365 nm irradiation. The decolorization rates fit a pseudo-first order reaction model. Under 254 nm irradiation and 6 mM oxidant addition, the decolorization rate constants (k) of H 2 O 2 , Na 2 S 2 O 8 , NaBrO 3 , and NaIO 4 for RR198 were 10.24, 17.93, 13.37, and 11.90 h -1 . Under 365 nm irradiation, 1 g/L TiO 2 and 1 mM NaIO 4 addition, the k values of the UV/TiO 2 , UV/NaIO 4 , and UV/TiO 2 /NaIO 4 systems were 0.50, 0.52, and 11.67 h -1 . The inhibition of RR198 decolorization by the addition ethanol indicates that the primary decolorization pathway involves hydroxyl radicals in UV/H 2 O 2 and UV/Na 2 S 2 O 8 systems, and that oxidation by other radicals is probably important in UV/NaBrO 3 and UV/NaIO 4 systems.

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Degradation of 4-chloro-2-methylphenol in aqueous solution by UV irradiation in the presence of titanium dioxide

Cited by 127 publications

References 37 publications

Photocatalytic Degradation of Monolinuron and Linuron in an Aqueous Suspension of Titanium Dioxide Under Simulated Solar Irradiation

Photocatalytic Degradation of Monolinuron and Linuron in an Aqueous Suspension of Titanium Dioxide Under Simulated Solar Irradiation

Visible Light Photoelectrocatalytic Degradation of Rhodamine B Using Ti/TiO2-NiO Photoanode

Decolorization of C.I. reactive red 198 in UV/oxidant and UV/TiO2/oxidant systems

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