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Surfactant-modifications of Na+—beidellite for the preparation of TiO2–Bd supported photocatalysts: II—Physico-chemical characterization and photocatalytic properties

Rhouta, Benaïssa and Bouna, Lahcen and Maury, Francis and Senocq, François and Lafont, Marie-Christine and Jada, Amane and Amjoud, M'barek and Daoudi, Lahcen Surfactant-modifications of Na+—beidellite for the preparation of TiO2–Bd supported photocatalysts: II—Physico-chemical characterization and photocatalytic properties. (2015) Applied Clay Science, 115. 266-274. ISSN 0169-1317

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Official URL: http://dx.doi.org/10.1016/j.clay.2015.04.025

Abstract

This work deals with the study of the effect of the amount of cethyltrimethylammonium bromide (CTAB) surfactant, used in the preparation of starting organobeidellites, on physico-chemical properties and photocatalytic activity of TiO2 supported beidellite (Bd) nanocomposites against the removal of Orange G (OG) dye from aqueous media. A structural study of organobeidellites used as starting materials was reported in a companion paper. Here, physico-chemical characterizations of the nanocomposite photocatalysts show that TiO2 supported on Bd beforehand organomodified with an amount of CTAB equivalent to 3 CEC of smectite (3CTA+–Bd) exhibits thin fine grained (≈ 10 nm) features which remarkably remained stable in the form of photoactive anatase up to 750 °C. Comparatively, the TiO2 coating grown on Bd previously rendered organophilic by using an amount of CTAB equivalent to 5 CEC of Clay mineral (5CTA+–Bd) appears thicker and more porous with larger nanoparticles (≈ 25 nm) which is prone to be readily converted into less photoactive rutile as observed near 700 °C. This is likely due to its development mainly outside Bd interlayer spaces promoted by outer organophilic environment created by the adsorption of CTA+ excess. In both cases, anatase is still present as minor phase up to 900 °C. As a result of these differences a significant improvement of the photocatalytic activity of TiO2 supported Bd nanocomposite prepared starting from 3CTA+–Bd is observed compared to that from 5CTA+–Bd. For instance, the total elimination of the pollutant from the aqueous solution occurs within about 45 min when using the 3CTA+–Bd–TiO2 photocatalyst instead of 90 min using the 5CTA+–Bd–TiO2 sample. Furthermore, the best TiO2–Bd supported photocatalyst is also found more efficient than a pure TiO2 xerogel sample.

Item Type:Article
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - INPT (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UPS (FRANCE)
Other partners > University of Cadi Ayyad - UCAM (MOROCCO)
Other partners > Université de Haute Alsace - UHA (FRANCE)
Laboratory name:
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Deposited By: Diane SAMELOR
Deposited On:12 Jan 2016 11:15

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