Adsorption and Photocatalytic Decomposition of Toluene on TiO2 Surfaces

Luo, Yi; Tai, Wei Sheng; Seo, Hyun Ook; Kim, Kwang-Dae; Kim, Myoung Joo; Dey, Nilay Kumar; Kim, Young Dok; Choi, Kang Ho; Lim, Dong Chan

doi:10.1007/s10562-010-0369-1

Cited by 17 publications

(4 citation statements)

References 25 publications

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“…It can be seen that for untreated catalysts the size of the particles goes for anatase between 9.1 and 22.9 nm being having bigger crystals for rutile. From the results, it can be deduced that the exposure of the catalysts to water do not change significantly the crystal sizes, which was in good agreement with (41). On the contrary, annealing of the catalysts increased the crystal size of both the anatase and the rutile phases.…”

Section: Crystal Size and Cristallinity Degreesupporting

confidence: 81%

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

Bengtsson¹,

Castellote²

2014

Mater. construcc.

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This paper analyzes the effect of some properties of different catalysts on the photocatalytic activity. The efficiency has been determined for two different processes: NOx abatement and self-cleaning for Rhodamine B and tobacco extract being, the TiO 2 based photocatalyst, supported as coatings on white mortar. Eight different catalysts were tested, seven commercial ones and one home-made catalyst with improved visible light absorption properties. Additionally, some of them were submitted to exposition to water and/or calcinations to alter their physical properties. A kinetic approach was used to evaluate the photocatalytic activity, being the first reaction constant (for NO) and just empirical constants (for self-cleaning) the parameters used for the comparison of the different materials. As a result, the efficiency, even for ranking, is dependent on the type of contaminant used in the experiment. In general, NO oxidation and tobacco followed similar trends while no clear relations were found for Rhodamine B. RESUMEN: Fotocatálisis heterogénea en materiales de construcción: efecto de las propiedades de los catalizadores en la eficiencia de degradación de NOx y autolimpieza.En este trabajo se analiza el efecto de las propiedades de distintos catalizadores en la actividad fotocatalítica de degradación de NOx y autolimpieza, para Rodamina B y extracto de tabaco. Se han ensayado ocho fotocatalizadores, basados en TiO 2 y soportados sobre mortero blanco; siete de ellos comerciales y uno sintetizado en el laboratorio con absorción mejorada en el visible. Adicionalmente, las propiedades físicas de algunos de ellos se alteraron mediante tratamientos con agua y/o por calcinación. La actividad fotocatalítica se ha evaluado mediante aproximación cinética, siendo la constante de reacción de primer orden (para NO) y constantes empíricas de ajuste (para autolimpieza) los parámetros de comparación entre materiales. Como resultado, la eficiencia depende del contaminante utilizado en el experimento de evaluación. En general, en este estudio, oxidación de NO y de extracto de tabaco presentan tendencias similares mientras para Rodamina B no se encontró correlación clara ninguna.

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Section: Crystal Size and Cristallinity Degreesupporting

confidence: 81%

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

Bengtsson¹,

Castellote²

2014

Mater. construcc.

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“…For photocatalytic degradation of volatile organic compounds (VOCs), not only the above issues but also quantitative description of the adsorption behavior on different facets and in-depth understanding of adsorption energies on different facets should be further investigated. In terms of gaseous toluene, one typical VOC, it was speculated that the weak bonding between the surface hydroxyl group and the aromatic ring of toluene adsorbed on TiO 2 was suggested to be the OH···π-electron-type interaction. − Therefore, the surface hydroxyl groups acting as active sites are crucial to toluene adsorption on the TiO 2 surface. , In this paper, the dominant {001} and {101} facets of anatase TiO 2 were controllably synthesized. The facet-dependent adsorption of toluene on TiO 2 was identified by using an in situ DRIFTS apparatus equipped with a homemade reaction system and a coupling gas-dosing system.…”

Section: Introductionmentioning

confidence: 97%

DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO₂ with Relative Photocatalytic Properties

et al. 2015

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Effective adsorption is of great importance to the photocatalytic degradation of volatile organic compounds. Herein, we succeeded in the preparation of anatase TiO2 with clean dominant {001} and {101} facets. By using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) equipped with a homemade reaction system and a coupling gas-dosing system, we found that TiO2 with dominant {001} facets exhibits higher toluene adsorption capacity than TiO2 with dominant {101} facets, which may be attributed to the different number of unsaturated 5c-Ti capable of forming the main active adsorption sites (terminal Ti-OH species). TiO2 with dominant {001} facets shows a significantly high photocatalytic degradation performance, with its degradation rate being 6 times higher than that of dominant {101} facets. Combined with simulation results, it is suggested that the synergetic effects of the formation of specific active adsorption sites, the low adsorption energy for toluene, and preservation of the free molecularly adsorbed water on the surface promote the degradation of gaseous toluene on the dominant {001} facets. This study exemplifies that the facet-dependent adsorption of volatile organic compounds is one of the most important factors to effectively engineer photocatalysts for air purification.

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“…Briefly, adsorbed species, including toluene ( v aromatic ring at 1601, 1580, and 1470 cm –1 and v CCH at 3056 cm –1 ) and benzaldehyde ( v CO at 1624 cm –1 and v C–C at 1280 cm –1 ), were observed on the surface of Ce 0.8 Mn 0.2 O 2 . Compared with those of pure CeO 2 and MnO x , the stretching vibrations of the methyl group at 2950 and 2850 cm –1 were prominently observed on the surface of Ce 0.8 Mn 0.2 O 2 (Figure a), suggesting the presence of adsorbed toluene, which may be caused by the interaction between the adsorption site and the toluene π-electron. ,, Moreover, a wide peak at approx. 3361 cm –1 ( v OH ) attributed to polymerized hydroxyl was observable when Ce 0.8 Mn 0.2 O 2 had been exposed to toluene .…”

Section: Resultsmentioning

confidence: 95%

Catalytic Oxidation Mechanism of Toluene over Ce_xMn_1–xO₂: The Role of Oxygen Vacancies in Adsorption and Activation of Toluene

Zhou

Song

et al. 2023

Langmuir

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Catalytic oxidation has been extensively studied as a promising technology for the removal of toluene from industrial waste gases and indoor air. However, the debate regarding the oxidation mechanism is far from resolved. Ce x Mn1–x O2 catalysts with different mixing ratios are prepared by the sol–gel method and found to exhibit better catalytic activities for toluene oxidation than a single oxide. Characterizations and theoretical calculations reveal that the doped Mn increases the number of oxygen vacancies and the ability of oxygen vacancies to activate aromatic rings, which promotes the rate-determining step of toluene oxidation, i.e., ring-opening reactions. The oxidation products detected by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and Vocus proton transfer reaction mass spectrometry (Vocus-PTR-MS) show that the doped Mn significantly improves the ring-opening efficiency and subsequently yields more short-chain products, such as pyruvic acid and acetic acid. A comprehensive oxidation pathway of toluene is refined in this work.

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Adsorption and Photocatalytic Decomposition of Toluene on TiO2 Surfaces

Cited by 17 publications

References 25 publications

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO₂ with Relative Photocatalytic Properties

Catalytic Oxidation Mechanism of Toluene over Ce_xMn_1–xO₂: The Role of Oxygen Vacancies in Adsorption and Activation of Toluene

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Adsorption and Photocatalytic Decomposition of Toluene on TiO2 Surfaces

Cited by 17 publications

References 25 publications

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

Heterogeneous photocatalysis on construction materials: effect of catalyst properties on the efficiency for degrading NOx and self cleaning

DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO2 with Relative Photocatalytic Properties

Catalytic Oxidation Mechanism of Toluene over CexMn1–xO2: The Role of Oxygen Vacancies in Adsorption and Activation of Toluene

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DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO₂ with Relative Photocatalytic Properties

Catalytic Oxidation Mechanism of Toluene over Ce_xMn_1–xO₂: The Role of Oxygen Vacancies in Adsorption and Activation of Toluene