Article
Photodegradation of 2,4-D over PdO/Al2O3-Nd 2O3 photocatalysts prepared by the sol-gel method
Fecha
2013Autor
Vargas, D.R.M.
Oviedo, M.J.
Da Silva Lisboa, F.
Wypych, F.
Hirata, G.A.
Arizaga, G.G.C.
Institución
Resumen
The layers of a Zn/Al layered double hydroxide (LDH) were doped with Dy3+ cations. Among some compositions, the Zn2+: Al 3+: Dy3+ molar ratio equal to 30: 9: 1 presented a single crystalline phase. Organic anions with carboxylic, amino, sulfate, or phosphate functional groups were intercalated as single layers between LDH layers as confirmed by X-ray diffraction and infrared spectroscopy. Photoluminescence spectra of the nitrate intercalated LDH showed a wide emission band with strong intensity in the yellow region (around 574 nm), originated due to symmetry distortion of the octahedral coordination in dysprosium centers. Moreover, a broad red band emission was also detected apparently due to the presence of zinc oxide. The distorted symmetry of the dysprosium coordination environment, also confirmed by X-ray photoelectron spectroscopy analysis, was modified after the intercalation with phenyl phosphonate (PP), aspartate (Asp), adipate (Adip), and serinate (Ser) anions; the emission as measured from PL spectra of these LDH was more intense in the blue region (ca. 486 nm), thus indicating an increase in symmetry of dysprosium octahedrons. The red emission band from zinc oxide kept the same intensity after intercalation of dodecyl sulfate (DDS). An additional emission of unknown origin at = 767 nm was present in all LDHs. " 2013 David Ricardo Martínez Vargas et al.",,,,,,"10.1155/2013/730153",,,"http://hdl.handle.net/20.500.12104/43586","http://www.scopus.com/inward/record.url?eid=2-s2.0-84888884496&partnerID=40&md5=d5de5d682972f70a5e802c7d7524ece6",,,,,,,,"Journal of Nanomaterials",,,,"2013",,"Scopus WOS",,,,,,,,,,,,"Phosphor dysprosium-doped layered double hydroxides exchanged with different organic functional groups",,"Article"
"45374","123456789/35008",,"Barrera, A., Universidad de Guadalajara, Centro Universitario de la Ciénega, Av. Universidad, Número 1115, Ocotlan Jal., Mexico; Tzompantzi, F., Universidad Autónoma Metropolitana - Iztapalapa, Departamento de Química, San Rafael Atlixco No. 186, Mexico 09340 D.F., Mexico; Lara, V., Universidad Autónoma Metropolitana - Iztapalapa, Departamento de Química, San Rafael Atlixco No. 186, Mexico 09340 D.F., Mexico; Gómez, R., Universidad Autónoma Metropolitana - Iztapalapa, Departamento de Química, San Rafael Atlixco No. 186, Mexico 09340 D.F., Mexico",,"Barrera, A. Tzompantzi, F. Lara, V. Gomez, R.",,"2012",,"The photocatalytic activity of 1.0 wt% PdO supported on Al 2O3-Nd2O3 binary oxides prepared by the sol-gel method was studied in the photodegradation of 2,4- dichlorophenoxyacetic acid (2,4-D). The photocatalysts were characterized by N2 physisorption, XRD and UV-vis spectroscopy. PdO supported on ?-Al2O3 photo-degrades the 2,4-D, however the addition of Nd2O3 to ?-Al2O3 notably improves the photocatalytic activity. As the concentration of Nd 2O3 in the binary oxide increases from 2 to 10 wt%, the photodegradation of 2,4-D is highly enhanced. The catalytic test for PdO supported on pure Nd2O3 showed scarce photocatalytic activity. Total organic carbon (TOC) analysis showed that the 2,4-D has been completely destroyed on the PdO/Al2O3-Nd2O 3 photocatalysts after 6 h under irradiation. " 2011 Elsevier B.V. All Rights Reserved.