Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology

The simultaneous photocatalytic reduction of Cr(VI) and oxidation of benzoic acid (BA) in aqueous suspensions using N-F-codoped TiO2 and simulated solar irradiation were investigated in the present study. Chemometric optimization tools such as response surface methodology (RSM) and experimental desi...

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Main Authors: Maria Antonopoulou, Aris Giannakas, Ioannis Konstantinou
Format: Article
Language:English
Published: Wiley 2012-01-01
Series:International Journal of Photoenergy
Online Access:http://dx.doi.org/10.1155/2012/520123
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author Maria Antonopoulou
Aris Giannakas
Ioannis Konstantinou
author_facet Maria Antonopoulou
Aris Giannakas
Ioannis Konstantinou
author_sort Maria Antonopoulou
collection DOAJ
description The simultaneous photocatalytic reduction of Cr(VI) and oxidation of benzoic acid (BA) in aqueous suspensions using N-F-codoped TiO2 and simulated solar irradiation were investigated in the present study. Chemometric optimization tools such as response surface methodology (RSM) and experimental design were used to model and optimize selected operational parameters of the simultaneous photocatalytic reduction of Cr(VI) and oxidation of BA. RSM was developed by considering a central composite design with three input variables, that are, N-F-codoped TiO2 mass, ratio of Cr/BA, and pH. The removal of Cr(VI) and BA in binary systems, containing both Cr(VI) and BA, showed a synergistic photocatalytic decontamination as BA significantly facilitated Cr(VI) reduction, whereas Cr(VI) accelerated also BA degradation. Due to the anionic-type adsorption onto TiO2 and its acid-catalyzed photocatalytic reduction, the removal of Cr(VI) decreased with increasing pH, while the degradation of BA followed also the same trend. Under the optimum conditions (N-F-TiO2) = 600 mg L−1, ratio of Cr(VI)/BA = 5, pH = 4, the removal for both Cr and BA followed a pseudo first-order kinetic model. It was found that the selected variables have significant effect both on Cr(VI) removal and BA degradation efficiency. The results revealed the feasibility and the effectiveness of using N-F-codoped TiO2 as photocatalyst for simultaneous decontamination of Cr(VI) and organic pollutants such as BA due to the appropriate oxidation and reduction ability of the photogenerated h+VB-e−CB pairs.
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spelling doaj-art-b5544a90631e4977961d1debd4a578962025-02-03T01:09:03ZengWileyInternational Journal of Photoenergy1110-662X1687-529X2012-01-01201210.1155/2012/520123520123Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface MethodologyMaria Antonopoulou0Aris Giannakas1Ioannis Konstantinou2Department of Environmental and Natural Resources Management, University of Western Greece, 30100 Agrinio, GreeceDepartment of Environmental and Natural Resources Management, University of Western Greece, 30100 Agrinio, GreeceDepartment of Environmental and Natural Resources Management, University of Western Greece, 30100 Agrinio, GreeceThe simultaneous photocatalytic reduction of Cr(VI) and oxidation of benzoic acid (BA) in aqueous suspensions using N-F-codoped TiO2 and simulated solar irradiation were investigated in the present study. Chemometric optimization tools such as response surface methodology (RSM) and experimental design were used to model and optimize selected operational parameters of the simultaneous photocatalytic reduction of Cr(VI) and oxidation of BA. RSM was developed by considering a central composite design with three input variables, that are, N-F-codoped TiO2 mass, ratio of Cr/BA, and pH. The removal of Cr(VI) and BA in binary systems, containing both Cr(VI) and BA, showed a synergistic photocatalytic decontamination as BA significantly facilitated Cr(VI) reduction, whereas Cr(VI) accelerated also BA degradation. Due to the anionic-type adsorption onto TiO2 and its acid-catalyzed photocatalytic reduction, the removal of Cr(VI) decreased with increasing pH, while the degradation of BA followed also the same trend. Under the optimum conditions (N-F-TiO2) = 600 mg L−1, ratio of Cr(VI)/BA = 5, pH = 4, the removal for both Cr and BA followed a pseudo first-order kinetic model. It was found that the selected variables have significant effect both on Cr(VI) removal and BA degradation efficiency. The results revealed the feasibility and the effectiveness of using N-F-codoped TiO2 as photocatalyst for simultaneous decontamination of Cr(VI) and organic pollutants such as BA due to the appropriate oxidation and reduction ability of the photogenerated h+VB-e−CB pairs.http://dx.doi.org/10.1155/2012/520123
spellingShingle Maria Antonopoulou
Aris Giannakas
Ioannis Konstantinou
Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
International Journal of Photoenergy
title Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
title_full Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
title_fullStr Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
title_full_unstemmed Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
title_short Simultaneous Photocatalytic Reduction of Cr(VI) and Oxidation of Benzoic Acid in Aqueous N-F-Codoped TiO2 Suspensions: Optimization and Modeling Using the Response Surface Methodology
title_sort simultaneous photocatalytic reduction of cr vi and oxidation of benzoic acid in aqueous n f codoped tio2 suspensions optimization and modeling using the response surface methodology
url http://dx.doi.org/10.1155/2012/520123
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