Photocatalytic degradation and mineralization of perfluorooctanoic acid (PFOA) using a composite TiO2 -rGO catalyst
| Autor: | Paula Ribao, Maria J. Rivero, Ane Urtiaga, Beatriz Gomez-Ruiz, Nazely Diban, Inmaculada Ortiz |
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| Přispěvatelé: | Universidad de Cantabria |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Environmental Engineering
Health Toxicology and Mutagenesis Radical Inorganic chemistry Oxide TiO2-rGO 02 engineering and technology 010501 environmental sciences 01 natural sciences Catalysis chemistry.chemical_compound Environmental Chemistry Photocatalysis Waste Management and Disposal 0105 earth and related environmental sciences Graphene oxide chemistry.chemical_classification PFOA Electron acceptor 021001 nanoscience & nanotechnology Pollution Decomposition chemistry Perfluorooctanoic acid Titanium dioxide 0210 nano-technology Fluoride |
| Zdroj: | Journal of Hazardous Materials, 2018, 344, 950-957 UCrea Repositorio Abierto de la Universidad de Cantabria instname |
| Popis: | The inherent resistance of perfluoroalkyl substances (PFASs) to biological degradation makes necessary to develop advanced technologies for the abatement of this group of hazardous substances. The present work investigated the photocatalytic decomposition of perfluorooctanoic acid (PFOA) using a composite catalyst based on TiO2 and reduced graphene oxide (95% TiO2/5% rGO) that was synthesized using a facile hydrothermal method. The efficient photoactivity of the TiO2-rGO (0.1 g L-1) composite was confirmed for PFOA (0.24 mmol L-1) degradation that reached 93 ± 7% after 12 h of UV-vis irradiation using a medium pressure mercury lamp, a great improvement compared to the TiO2 photocatalysis (24 ± 11% PFOA removal) and direct photolysis (58 ± 9%). These findings indicate that rGO provided the suited properties of TiO2-rGO, possibly as a result of acting as electron acceptor and avoiding the high recombination electron/hole pairs. The release of fluoride and the formation of shorter-chain perfluorocarboxilyc acids, that were progressively eliminated in a good match with the analysed reduction of total organic carbon, is consistent with a step-by-step PFOA decomposition via photogenerated hydroxyl radicals. Finally, the apparent first order rate constants of the TiO2-rGO UV-vis PFOA decompositions, and the intermediate perfluorcarboxylic acids were found to increase as the length of the carbon chain was shorter. Financial support from projects CTM2013-44081-R, CTM2015-69845-R and CTM2016-75509-R (MINECO, SPAIN-FEDER 2014–2020) is acknowledged. B. Gomez thanks the FPI scholarship (BES-2014-071045). |
| Databáze: | OpenAIRE |
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