Photoelectrochemical behavior of alizarin modified TiO2 films

Photocurrent voltage curves obtained under visible light excitation of alizarin molecules chemisorbed to nanoporous TiO2 films show both anodic and cathodic currents. The potential at which the sign reversal occurs depends on the electrolyte pH, the presence of acceptors, and the dye coverage, but a...

Descripción completa

Detalles Bibliográficos
Autores principales: Rodríguez, Hernán Bernardo, San Roman, Enrique Arnoldo
Publicado: 2010
Materias:
Cathodic currents
Cathodic photocurrent
Electrolyte solutions
Electron discharge
Flat band potential
matrix
Nanoporous TiO
pH value
Photocurrent-voltage curve
Photoelectrochemical behavior
Sign reversal
Surface state
TiO
Visible light excitation
Chemisorption
Photocurrents
Semiconductor quantum wells
Electrolytes
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n26_p11515_DiIorio
http://hdl.handle.net/20.500.12110/paper_19327447_v114_n26_p11515_DiIorio
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_19327447_v114_n26_p11515_DiIorio
record_format dspace
spelling paper:paper_19327447_v114_n26_p11515_DiIorio2023-06-08T16:31:29Z Photoelectrochemical behavior of alizarin modified TiO2 films Rodríguez, Hernán Bernardo San Roman, Enrique Arnoldo Cathodic currents Cathodic photocurrent Electrolyte solutions Electron discharge Flat band potential matrix Nanoporous TiO pH value Photocurrent-voltage curve Photoelectrochemical behavior Sign reversal Surface state TiO Visible light excitation Chemisorption Photocurrents Semiconductor quantum wells Electrolytes Photocurrent voltage curves obtained under visible light excitation of alizarin molecules chemisorbed to nanoporous TiO2 films show both anodic and cathodic currents. The potential at which the sign reversal occurs depends on the electrolyte pH, the presence of acceptors, and the dye coverage, but as a general rule, it occurs at potentials ca. 600-700 mV more positive than the flat band potential. Negative photocurrents are accounted by efficient electron discharge to the electrolyte mediated by the ligand. Cathodic photocurrents are only observed at pH values higher than ca. 4.0 and go through a maximum at intermediate alizarin loadings. This phenomenon is ascribed to the progressive reparation of surface states by alizarin which hampers carrier transport through the TiO2 matrix and decreases electron discharge to the electrolyte solution. © 2010 American Chemical Society. Fil:Rodríguez, H.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:San Román, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n26_p11515_DiIorio http://hdl.handle.net/20.500.12110/paper_19327447_v114_n26_p11515_DiIorio
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cathodic currents
Cathodic photocurrent
Electrolyte solutions
Electron discharge
Flat band potential
matrix
Nanoporous TiO
pH value
Photocurrent-voltage curve
Photoelectrochemical behavior
Sign reversal
Surface state
TiO
Visible light excitation
Chemisorption
Photocurrents
Semiconductor quantum wells
Electrolytes
spellingShingle Cathodic currents
Cathodic photocurrent
Electrolyte solutions
Electron discharge
Flat band potential
matrix
Nanoporous TiO
pH value
Photocurrent-voltage curve
Photoelectrochemical behavior
Sign reversal
Surface state
TiO
Visible light excitation
Chemisorption
Photocurrents
Semiconductor quantum wells
Electrolytes
Rodríguez, Hernán Bernardo
San Roman, Enrique Arnoldo
Photoelectrochemical behavior of alizarin modified TiO2 films
topic_facet Cathodic currents
Cathodic photocurrent
Electrolyte solutions
Electron discharge
Flat band potential
matrix
Nanoporous TiO
pH value
Photocurrent-voltage curve
Photoelectrochemical behavior
Sign reversal
Surface state
TiO
Visible light excitation
Chemisorption
Photocurrents
Semiconductor quantum wells
Electrolytes
description Photocurrent voltage curves obtained under visible light excitation of alizarin molecules chemisorbed to nanoporous TiO2 films show both anodic and cathodic currents. The potential at which the sign reversal occurs depends on the electrolyte pH, the presence of acceptors, and the dye coverage, but as a general rule, it occurs at potentials ca. 600-700 mV more positive than the flat band potential. Negative photocurrents are accounted by efficient electron discharge to the electrolyte mediated by the ligand. Cathodic photocurrents are only observed at pH values higher than ca. 4.0 and go through a maximum at intermediate alizarin loadings. This phenomenon is ascribed to the progressive reparation of surface states by alizarin which hampers carrier transport through the TiO2 matrix and decreases electron discharge to the electrolyte solution. © 2010 American Chemical Society.
author Rodríguez, Hernán Bernardo
San Roman, Enrique Arnoldo
author_facet Rodríguez, Hernán Bernardo
San Roman, Enrique Arnoldo
author_sort Rodríguez, Hernán Bernardo
title Photoelectrochemical behavior of alizarin modified TiO2 films
title_short Photoelectrochemical behavior of alizarin modified TiO2 films
title_full Photoelectrochemical behavior of alizarin modified TiO2 films
title_fullStr Photoelectrochemical behavior of alizarin modified TiO2 films
title_full_unstemmed Photoelectrochemical behavior of alizarin modified TiO2 films
title_sort photoelectrochemical behavior of alizarin modified tio2 films
publishDate 2010
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_19327447_v114_n26_p11515_DiIorio
http://hdl.handle.net/20.500.12110/paper_19327447_v114_n26_p11515_DiIorio
work_keys_str_mv AT rodriguezhernanbernardo photoelectrochemicalbehaviorofalizarinmodifiedtio2films
AT sanromanenriquearnoldo photoelectrochemicalbehaviorofalizarinmodifiedtio2films
_version_ 1768542102589800448

Ejemplares similares