Concentrate and degrade PFOA with a photo-regenerable composite of In-doped TNTs@AC.

Autor: Arana Juve JM; Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark., Li F; Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Science and Engineering, Peking University, Beijing, 100871, China., Zhu Y; Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA., Liu W; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Science and Engineering, Peking University, Beijing, 100871, China., Ottosen LDM; Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark., Zhao D; Environmental Engineering Program, Department of Civil & Environmental Engineering, Auburn University, Auburn, AL, 36849, USA. Electronic address: zhaodon@auburn.edu., Wei Z; Centre for Water Technology (WATEC), Department of Biological and Chemical Engineering, Aarhus University, Universitetsbyen 36, 8000, Aarhus C, Denmark. Electronic address: zwei@bce.au.dk.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2022 Aug; Vol. 300, pp. 134495. Date of Electronic Publication: 2022 Apr 04.
DOI: 10.1016/j.chemosphere.2022.134495
Abstrakt: "Concentrate-and-degrade" is an effective strategy to promote mass transfer and degradation of pollutants in photocatalytic systems, yet suitable and cost-effective photocatalysts are required to practice the new concept. In this study, we doped a post-transition metal of Indium (In) on a novel composite adsorptive photocatalyst, activated carbon-supported titanate nanotubes (TNTs@AC), to effectively degrade perfluorooctanoic acid (PFOA). In/TNTs@AC exhibited both excellent PFOA adsorption (>99% in 30 min) and photodegradation (>99% in 4 h) under optimal conditions (25 °C, pH 7, 1 atm, 1 g/L catalyst, 0.1 mg/L PFOA, 254 nm). The heterojunction structure of the composite facilitated a cooperative adsorption mode of PFOA, i.e., binding of the carboxylic head group of PFOA to the metal oxide and attachment of the hydrophobic tail to AC. The resulting side-on adsorption mode facilitates the electron (e ‒ ) transfer from the carboxylic head to the photogenerated hole (h + ), which was the major oxidant verified by scavenger tests. Furthermore, the presence of In enables direct electron transfer and facilitates the subsequent stepwise defluorination. Finally, In/TNTs@AC was amenable to repeated uses in four consecutive adsorption-photodegradation runs. The findings showed that adsorptive photocatalysts can be prepared by hybridization of carbon and photoactive semiconductors and the enabled "concentrate-and-degrade" strategy is promising for the removal and degradation of trace levels of PFOA from polluted waters.
(Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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