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Revista mexicana de ingeniería química

versão impressa ISSN 1665-2738

Rev. Mex. Ing. Quím vol.13 no.2 Ciudad de México Ago. 2014


Artículos regulares/Catálisis, cinética y reactores


Electron paramagnetic resonance (EPR) investigation of TiO2-delaminated clays


Investigación por resonancia paramagnética electrónica (EPR) de arcillas delaminadas con TiO2


J.G. Carriazo1*, A. Ensuncho-Muñoz2 and O. Almanza3


1 Departamento de Química, Universidad Nacional de Colombia, Sede Bogotá. Ciudad Universitaria, Carrera 30, N° 45-03, Bogotá, D. C. (Colombia). *Autor para la correspondencia. E-mail:

2 Departamento de Química, Facultad de Ciencias Básicas e Ingeniería, Universidad de Córdoba. Montería, Colombia.

3 Departamento de Física, Universidad Nacional de Colombia, Sede Bogotá. Ciudad Universitaria, Carrera 30, N° 45-03, Bogotá, D. C. (Colombia).


Received February 16, 2013.
Accepted March 15, 2014.



In this paper a set of TiO2 and Fe/TiO2 delaminated clays, prepared by different synthesis procedures, was characterized by electron paramagnetic resonance (EPR) spectroscopy. EPR analyses revealed an important shift of the central g-value as consequence of Fe3+ insertion (substitution) in the TiO2 structure by a sensitive and direct method of iron incorporation. A series of additional g-values, symmetrically distributed around the central absorption line, was attributed to some electron trapping sites (defects) remained in the TiO2 framework. The spectroscopic characterizations carried out in this work contribute to understand the photo-catalytic properties previously observed for these solids.

Keywords: delaminated clay, titanium dioxide, EPR, iron-titanium modified clay, clay mineral.



El presente artículo muestra la caracterización, mediante espectroscopía de resonancia paramagnética electrónica (EPR), de un conjunto de arcillas delaminadas con TiO2 y Fe/TiO2 obtenidas por diferentes procedimientos de síntesis. Los análisis de EPR mostraron un desplazamiento importante del valor "g" central como consecuencia de la inserción de Fe3+ por substitución en la estructura de TiO2 mediante un método sensible y directo de incorporación de los iones hierro (III). Adicionalmente, se observó un conjunto de valores g simétricamente distribuidos alrededor de la línea del valor g central, las cuales se atribuyen a sitios de electrones atrapados en vacancias (defectos) de la estructura de TiO2. La caracterización espectroscópica realizada en este trabajo contribuye a la comprensión de las propiedades fotocatalíticas previamente observadas para los sólidos sintetizados.

Palabras clave: arcilla delaminada, dióxido de titanio, EPR, arcilla modificada con hierro-titanio, mineral de arcilla.





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