ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE

This work reports the degradation of methylene blue (MB) on Ti/TiO2 and Ti/TiO2/Fe-allophane electrodes in a pH 3 using 0.1 M Na2SO4 as support electrolyte. SEM micrographs show a homogeneous distribution of TiO2 over the whole electrode surface forming nanotubes and nanopores. Fe-allophane modified...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	LEZANA,NICOLE, FERNÁNDEZ-VIDAL,FRANCISCO, BERRÍOS,CRISTHIAN, GARRIDO-RAMÍREZ,ELIZABETH
Lenguaje:	English
Publicado:	Sociedad Chilena de Química 2017
Materias:	Ti/TiO2 Fe-Allophane methylene blue electrochemical and photoelectrochemical oxidation
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072017000200021
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0717-97072017000200021
record_format	dspace
spelling	oai:scielo:S0717-970720170002000212017-06-30ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANELEZANA,NICOLEFERNÁNDEZ-VIDAL,FRANCISCOBERRÍOS,CRISTHIANGARRIDO-RAMÍREZ,ELIZABETH Ti/TiO2 Fe-Allophane methylene blue electrochemical and photoelectrochemical oxidation This work reports the degradation of methylene blue (MB) on Ti/TiO2 and Ti/TiO2/Fe-allophane electrodes in a pH 3 using 0.1 M Na2SO4 as support electrolyte. SEM micrographs show a homogeneous distribution of TiO2 over the whole electrode surface forming nanotubes and nanopores. Fe-allophane modified electrode shows the formation of large-grains agglomerate on the electrode surface due to allophane, which provides a greater surface area to the electrode due to meso and micropore structures. Preliminary cyclic voltammetry show that Ti/TiO2 has the typical voltammetric response due to Ti(III)/Ti(IV) pair. Diffusional problems were observed through of the film when the electrode is modified with Fe-allophane modifying the quasi-reversible process Ti(III)/Ti(IV). Different kind of methodologies in the degradation process were used: Electrochemistry (EC), Photochemistry (PC), Photoelectrochemistry (PEC) and Adsorption (Ads). These methods were developing to discard any reaction or interaction that is not of interest. On Ti/TiO2 with PC and Ads methodologies was not observed any activity to MB degradation showing that is not photosensitive and that the interaction between this and surface electrode is low. But with EC and PEC degradation to 55% is reached after 3 hours of electrolysis. With Ti/TiO2-Fe-allophane electrodes are observed a higher activity for all methodologies. The PC and Ads methods show that the MB degradation reaches to ~20 % of the initial concentration. As mentioned above, the PC and Ads processes no show degradation on Ti/TiO2, therefore the degradation it only due to the adsorption of MB in/on allophane coat behaving as concentrator matrix. A lower improvement is observed with EC process when is incorporated Ti/TiO2-Fe-allophane is due to the barrier of the electrode surface by oxidation products. With PEC is reached the higher degradation value of ~88 %, showing an improvement of the degradation with the presence of Fe-allophane. The results indicate that the main role of Fe-allophane on the electrode is similar to a concentrator matrix.info:eu-repo/semantics/openAccessSociedad Chilena de QuímicaJournal of the Chilean Chemical Society v.62 n.2 20172017-06-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072017000200021en10.4067/S0717-97072017000200021
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	Ti/TiO2 Fe-Allophane methylene blue electrochemical and photoelectrochemical oxidation
spellingShingle	Ti/TiO2 Fe-Allophane methylene blue electrochemical and photoelectrochemical oxidation LEZANA,NICOLE FERNÁNDEZ-VIDAL,FRANCISCO BERRÍOS,CRISTHIAN GARRIDO-RAMÍREZ,ELIZABETH ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
description	This work reports the degradation of methylene blue (MB) on Ti/TiO2 and Ti/TiO2/Fe-allophane electrodes in a pH 3 using 0.1 M Na2SO4 as support electrolyte. SEM micrographs show a homogeneous distribution of TiO2 over the whole electrode surface forming nanotubes and nanopores. Fe-allophane modified electrode shows the formation of large-grains agglomerate on the electrode surface due to allophane, which provides a greater surface area to the electrode due to meso and micropore structures. Preliminary cyclic voltammetry show that Ti/TiO2 has the typical voltammetric response due to Ti(III)/Ti(IV) pair. Diffusional problems were observed through of the film when the electrode is modified with Fe-allophane modifying the quasi-reversible process Ti(III)/Ti(IV). Different kind of methodologies in the degradation process were used: Electrochemistry (EC), Photochemistry (PC), Photoelectrochemistry (PEC) and Adsorption (Ads). These methods were developing to discard any reaction or interaction that is not of interest. On Ti/TiO2 with PC and Ads methodologies was not observed any activity to MB degradation showing that is not photosensitive and that the interaction between this and surface electrode is low. But with EC and PEC degradation to 55% is reached after 3 hours of electrolysis. With Ti/TiO2-Fe-allophane electrodes are observed a higher activity for all methodologies. The PC and Ads methods show that the MB degradation reaches to ~20 % of the initial concentration. As mentioned above, the PC and Ads processes no show degradation on Ti/TiO2, therefore the degradation it only due to the adsorption of MB in/on allophane coat behaving as concentrator matrix. A lower improvement is observed with EC process when is incorporated Ti/TiO2-Fe-allophane is due to the barrier of the electrode surface by oxidation products. With PEC is reached the higher degradation value of ~88 %, showing an improvement of the degradation with the presence of Fe-allophane. The results indicate that the main role of Fe-allophane on the electrode is similar to a concentrator matrix.
author	LEZANA,NICOLE FERNÁNDEZ-VIDAL,FRANCISCO BERRÍOS,CRISTHIAN GARRIDO-RAMÍREZ,ELIZABETH
author_facet	LEZANA,NICOLE FERNÁNDEZ-VIDAL,FRANCISCO BERRÍOS,CRISTHIAN GARRIDO-RAMÍREZ,ELIZABETH
author_sort	LEZANA,NICOLE
title	ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
title_short	ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
title_full	ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
title_fullStr	ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
title_full_unstemmed	ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE
title_sort	electrochemical and photo-electrochemical processes of methylene blue oxidation by ti/tio2 electrodes modified with fe-allophane
publisher	Sociedad Chilena de Química
publishDate	2017
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072017000200021
work_keys_str_mv	AT lezananicole electrochemicalandphotoelectrochemicalprocessesofmethyleneblueoxidationbytitio2electrodesmodifiedwithfeallophane AT fernandezvidalfrancisco electrochemicalandphotoelectrochemicalprocessesofmethyleneblueoxidationbytitio2electrodesmodifiedwithfeallophane AT berrioscristhian electrochemicalandphotoelectrochemicalprocessesofmethyleneblueoxidationbytitio2electrodesmodifiedwithfeallophane AT garridoramirezelizabeth electrochemicalandphotoelectrochemicalprocessesofmethyleneblueoxidationbytitio2electrodesmodifiedwithfeallophane
_version_	1714200912495378432

ELECTROCHEMICAL AND PHOTO-ELECTROCHEMICAL PROCESSES OF METHYLENE BLUE OXIDATION BY Ti/TiO2 ELECTRODES MODIFIED WITH FE-ALLOPHANE

Ejemplares similares