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Krylov IB, Lopat’eva ER, Subbotina IR, Nikishin GI, Yu B, Terent’ev AO. Mixed hetero-/homogeneous TiO2/N-hydroxyimide photocatalysis in visible-light-induced controllable benzylic oxidation by molecular oxygen. CHINESE JOURNAL OF CATALYSIS 2021. [DOI: 10.1016/s1872-2067(21)63831-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Fessi N, Nsib MF, Chevalier Y, Guillard C, Dappozze F, Houas A, Palmisano L, Parrino F. Pickering Emulsions of Fluorinated TiO 2: A New Route for Intensification of Photocatalytic Degradation of Nitrobenzene. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13545-13554. [PMID: 33147976 PMCID: PMC7676287 DOI: 10.1021/acs.langmuir.0c02285] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Fluorination of the TiO2 surface has been often reported as a tool to increase the photocatalytic efficiency due to the beneficial effects in terms of production of oxidizing radicals. Moreover, it is shown that the unique amphiphilic properties of the fluorinated TiO2 (TiO2-F) surface allow one to use this material as a stabilizer for the formulation of Pickering emulsions of poorly soluble pollutants such as nitrobenzene (NB) in water. The emulsions have been characterized in terms of size of the droplets, type of emulsion, possibility of phase inversion, contact angle measurements, and optical microscopy. The emulsified system presents micrometer-sized droplets of pollutant surrounded by the TiO2-F photocatalyst. Consequently, the system can be considered to be composed of microreactors for the degradation of the pollutant, which maximize the contact area between the photocatalyst and substrate. The enhanced photocatalytic activity of TiO2-F was confirmed in the present paper as the apparent rate constants of NB photodegradation were 16 × 10-3 and 12 × 10-3 min-1 for fluorinated and bare TiO2, respectively. At NB concentrations largely exceeding its solubility, the rate constant was 0.04 × 10-3 min-1 in the presence of both TiO2 and TiO2-F. However, unlike TiO2, TiO2-F stabilized NB/water emulsions and, under these conditions, the efficiency of NB photocatalytic degradation in the emulsified system was ca. 18 times higher than in the nonemulsified one. This result is relevant also in terms of practical applications because it opens the route to one-pot treatments of biphasic polluted streams without the need of preliminary physical separation treatments.
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Affiliation(s)
- Nidhal Fessi
- Laboratoire
de Recherche Catalyse et Matériaux pour l’Environnement
et les Procédés LRCMEP (UR11ES85), Faculté des
Sciences de Gabès, University of
Gabès, Campus Universitaire, Cité Erriadh, 6072 Gabès, Tunisia
- University
of Lyon, Laboratoire d’Automatique et de Génie des Procédés
(LAGEPP), UMR 5007 CNRS, University Claude Bernard Lyon 1, 43 Boulevard 11 Novembre, 69622 Villeurbanne, France
| | - Mohamed Faouzi Nsib
- Laboratoire
de Recherche Catalyse et Matériaux pour l’Environnement
et les Procédés LRCMEP (UR11ES85), Faculté des
Sciences de Gabès, University of
Gabès, Campus Universitaire, Cité Erriadh, 6072 Gabès, Tunisia
- Higher
School of Sciences and Technology, University
of Sousse, Rue Tahar
Ben Achour, 4003 Sousse, Tunisia
| | - Yves Chevalier
- University
of Lyon, Laboratoire d’Automatique et de Génie des Procédés
(LAGEPP), UMR 5007 CNRS, University Claude Bernard Lyon 1, 43 Boulevard 11 Novembre, 69622 Villeurbanne, France
| | - Chantal Guillard
- University
of Lyon, Institut de Recherches sur la Catalyse et l’Environnement
de Lyon (IRCELYON), UMR 5256 CNRS, Université Claude Bernard
Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne, France
| | - Frédéric Dappozze
- University
of Lyon, Institut de Recherches sur la Catalyse et l’Environnement
de Lyon (IRCELYON), UMR 5256 CNRS, Université Claude Bernard
Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne, France
| | - Ammar Houas
- Laboratoire
de Recherche Catalyse et Matériaux pour l’Environnement
et les Procédés LRCMEP (UR11ES85), Faculté des
Sciences de Gabès, University of
Gabès, Campus Universitaire, Cité Erriadh, 6072 Gabès, Tunisia
| | - Leonardo Palmisano
- Dipartimento
di Ingegneria, University of Palermo, Viale delle Scienze Edificio 6, 90128 Palermo, Italy
| | - Francesco Parrino
- Department
of Industrial Engineering, University of
Trento, Via Sommarive
9, 38123 Trento, Italy
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Subbotina IR, Barsukov DV. Direct evidence of the key role of UV-formed peroxide species in photocatalytic gas-solid oxidation in air on anatase TiO 2 particles. Phys Chem Chem Phys 2020; 22:2200-2211. [PMID: 31912826 DOI: 10.1039/c9cp04728j] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
IR spectroscopy was applied for the in situ investigations of surface intermediates formed on the surface of TiO2 (anatase) and ZnO under UV light illumination in air and their reactivity in the elimination of simple pollutant molecules. UV-irradiation of TiO2 (anatase) in air leads to the generation of peroxo-species with the peaks at 852 and 912 cm-1, but the bands of O2˙-ads were not detected. This is, to our knowledge, the first direct in situ IR spectroscopic detection of O2 photosorption intermediates in moist air. The formation of peroxo-species in these conditions is specific for TiO2 (anatase), whereas on ZnO the predominant species under UV light illumination in air are O2˙-ads and H2O2, desorbing into gas phase. Adsorbed water and surface hydroxyl groups contribute to the formation and stabilization of peroxo-species on TiO2 anatase during UV illumination in an oxygen atmosphere. If UV-irradiation is carried out in the environment of moist argon instead of moist air, the peroxo-species on TiO2 anatase are formed from water in a negligible quantity. Peroxo-species formed after O2 photoadsorption on TiO2 anatase in moist air have band positions similar to peroxo-species formed after photodecomposition of H2O2 (with accompanying color change of this sample from yellow to white). Direct experimental IR-spectroscopic evidence of peroxo-species reactivity as oxidative intermediates on TiO2 (anatase) in CO and ethanol vapor photooxidative processes is firstly obtained. These results confirm our early conclusion that peroxo-species formed under UV-irradiation in O2 on the hydrated surface of TiO2 (anatase) can be responsible for the surprising extreme dependence of the CO photooxidation rate on the adsorbed water coverage with the maximum at ∼0.5 ML. The ZnO sample was not active in the photooxidation of these molecules in air. It is concluded that UV formed peroxo-species are important diamagnetic oxidative intermediates in heterogeneous photochemical gas-solid oxidation processes on TiO2 (anatase).
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Affiliation(s)
- Irina Rudol'fovna Subbotina
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences Leninsky Prospect 47, Moscow 119991, Russia.
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Khazaee Z, Mahjoub AR, Cheshme Khavar AH, Srivastava V, Sillanpää M. Synthesis of layered perovskite Ag,F-Bi2MoO6/rGO: A surface plasmon resonance and oxygen vacancy promoted nanocomposite as a visible-light photocatalyst. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.04.046] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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