Preservation of the photocatalytic activity of TiO2 by EDTA in the reductive transformation of Cr(VI). Studies by Time Resolved Microwave Conductivity
| Autor: | Marta I. Litter, Christophe Colbeau-Justin, Graciela Custo, Jorge M. Meichtry |
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| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Kinetics
Inorganic chemistry Otras Ingeniería del Medio Ambiente Irradiation time INGENIERÍAS Y TECNOLOGÍAS Organic compound Catalysis Microwave conductivity Irradiation Ingeniería del Medio Ambiente Deposition (law) chemistry.chemical_classification CR(VI) TRMC Otras Ciencias Químicas EDTA Ciencias Químicas General Chemistry Ingeniería Química chemistry Otras Ingeniería Química Photocatalysis TIO2 PHOTOCATALYSIS CIENCIAS NATURALES Y EXACTAS |
| Popis: | P25 TiO2 was found to be deactivated after Cr(VI) (0.8 mM) photocatalytic experiments at pH 2 in the absence of EDTA, but this deactivation was not found in the presence of the organic compound (2 mM), which preserves the activity of the photocatalyst. The results were confirmed by TRMC measurements. The preservation of the activity by the presence of EDTA can be a general behavior of reducing oligocarboxylic acids present together with Cr(VI) in the photocatalytic system, where Cr(III) soluble complexes can be formed and Cr(III) deposition onto the TiO2 surface is prevented. The treatment of a set of diluted Cr(VI) solutions (0.8 mM) in successive experiments with the reused photocatalyst was more efficient for Cr(VI) removal in the presence of EDTA (2 mM, 700 s total irradiation time) than the use of a more concentrated sample (Cr(VI), EDTA) with the same photocatalyst submitted to a longer irradiation (900 s), indicating a good strategy for application. A change in the kinetics from a pseudo-first order at the lowest concentration to an almost zero order at the highest concentration takes place and is analyzed. Fil: Meichtry, Jorge Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Colbeau Justin, Christophe. Universite de Paris XI. Laboratoire de Chimie Physique; Francia. Centre National de la Recherche Scientifique; Francia Fil: Custo, Graciela Susana. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina Fil: Litter, Marta Irene. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Seguridad Nuclear y Ambiente. Gerencia de Química (CAC); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina |
| Databáze: | OpenAIRE |
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