Magnetically recoverable TiO2-WO3 photocatalyst to oxidize bisphenol A from model wastewater under simulated solar light
A novel magnetically recoverable, visible light active TiO2-WO3 composite (Fe3O4@SiO2@TiO2-WO3) was prepared to enable the photocatalyst recovery after the degradation of bisphenol A (BPA) under simulated solar light. For comparison, the photocatalytic activity of other materials such as non-magnetic TiO2-WO3, Fe3O4@SiO2@TiO2, TiO2, and the commercial TiO2 P25 was also evaluated under the studied experimental conditions. The structure and morphology of the synthesized materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and electron dispersion spectroscopy (EDS). Moreover, Brunauer-Emmett-Teller (BET) surface area and magnetic properties of the samples were determined. The Fe3O4@SiO2@TiO2-WO3 and TiO2-WO3 led to a BPA degradation of 17.50 and 27.92 %, respectively, after 2 h of the simulated solar light irradiation. Even though their activity was lower than that of P25, which degraded completely BPA after 1 h, our catalysts were magnetically separable for their further reuse in the treatment. Furthermore, the influence of the water matrix in the photocatalytic activity of the samples was studied in municipal wastewater. Finally, the identification of reaction intermediates was performed and a possible BPA degradation pathway was proposed to provide a better understanding of the degradation process.
KeywordsBisphenol A (BPA) Degradation pathway Magnetic composite Photocatalysis TiO2 WO3
Financial support from the Spanish Ministry of Economy and Competitiveness and from FEDER funds (projects CTM2012-33917, CTM2015-69845-R and CTQ2015-66078-R) are gratefully acknowledged (MINECO/FEDER, UE). Sara Dominguez also thanks the FPI postgraduate research grant (BES-2013-064055) and the predoctoral mobility aid for conducting short stays in R&D Centers (EEBB-I-15-09465).
- Da Silva JCC, Teodoro JAR, De Cássia Franco Afonso RJ, Aquino SF, Augusti R (2014) Photodegradation of bisphenol A in aqueous medium: monitoring and identification of by-products by liquid chromatography coupled to high-resolution mass spectrometry. Rapid Commun Mass Spectrom 28:987–994. doi: 10.1002/rcm.6863 CrossRefGoogle Scholar
- Dimitroula H, Daskalaki VM, Frontistis Z, Kondarides DI, Panagiotopoulou P, Xekoukoulotakis NP, Mantzavinos D (2012) Solar photocatalysis for the abatement of emerging micro-contaminants in wastewater: synthesis, characterization and testing of various TiO2 samples. Appl Catal B: Environ 117–118:283–291. doi: 10.1016/j.apcatb.2012.01.024 CrossRefGoogle Scholar
- Dominguez S, Ribao P, Rivero MJ, Ortiz I (2015) Influence of radiation and TiO2 concentration on the hydroxyl radicals generation in a photocatalytic LED reactor. Application to dodecylbenzenesulfonate degradation. Appl Catal B Environ 178:165–169. doi: 10.1016/j.apcatb.2014.09.072 CrossRefGoogle Scholar
- Han C, Likodimos V, Khan JA, Nadagouda MN, Andersen J, Falaras P, Rosales-Lombardi P, Dionysiou DD (2014) UV-visible light-activated Ag-decorated, monodisperse TiO2 aggregates for treatment of the pharmaceutical oxytetracycline. Environ Sci Pollut Res 21:11781–11793. doi: 10.1007/s11356-013-2233-5 CrossRefGoogle Scholar
- Kou Y, Yang J, Li B, Fu S (2015) Solar photocatalytic activities of porous Nb-doped TiO microspheres by coupling with tungsten oxide. Mater Res Bull 63:105–111. doi: 10.1016/j.materresbull.2014.11.050
- Pelaez M, Nolan NT, Pillai SC, Seery MK, Falaras P, Kontos AG, Dunlop PSM, Hamilton JWJ, Byrne JA, O’Shea K, Entezari MH, Dionysiou DD (2012) A review on the visible light active titanium dioxide photocatalysts for environmental applications. Appl Catal B Environ 125:331–349. doi: 10.1016/j.apcatb.2012.05.036 CrossRefGoogle Scholar
- Ramos-Delgado NA, Gracia-Pinilla MA, Maya-Treviño L, Hinojosa-Reyes L, Guzman-Mar JL, Hernández-Ramírez A (2013) Solar photocatalytic activity of TiO2 modified with WO3 on the degradation of an organophosphorus pesticide. J Hazard Mater 263P:36–44. doi: 10.1016/j.jhazmat.2013.07.058 CrossRefGoogle Scholar
- Sin JC, Lam SM, Mohamed AR, Lee KT (2012) Degrading endocrine disrupting chemicals from wastewater by TiO2 photocatalysis: a review. Int J Photoenergy 185159. doi: 10.1155/2012/185159