Electrochemically grown self-organized hematite nanotube arrays for photoelectrochemical water splitting

Ricardo Schrebler, Luis A. Ballesteros, Humberto Gómez, Paula Grez, Ricardo Córdova, EDUARDO CARLO MUÑOZ CARTAGENA, Rodrigo Schrebler, J. R. Ramos-Barrado, Enrique A. Dalchiele

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

31 Citas (Scopus)

Resumen

Hematite nanostructures were electrochemically grown by ultrasound-assisted anodization of iron substrates in an ethylene glycol based medium. These hematite nano-architectures can be tuned from a 1-D nanoporous layer to a self-organized nanotube one if the grown is done onto a bare iron foil substrate or onto an electrochemical pretreated one, respectively. Depending upon the pre-treatment conditioning, the self-organized nanotube layer consists of nanotube arrays with a single tube inner diameter of approximately 40-50 nm and wall thickness of 20-30 nm. Their morphological, structural and optoelectronic properties are studied. The photoelectrochemical properties of the resulting hematite nanostructures are studied from the point of view of their application as photoanodes in splitting of water. Through the photocurrent transients for the three nanostructured hematite type electrodes under study, the rate constants ktr and krec corresponding to the rate constant of charge transfer and recombination processes have been determined. In all cases, the potential value where ktr > krec was attained at more negative values than the reversible potential of water oxidation, indicating a photocatalytic effect. All samples show a maximum IPCE value between 350 and 375 nm, being the samples pretreated at -1.0 V which shows the highest IPCE value: 45% at 375 nm.

Idioma originalInglés
Páginas (desde-hasta)H903-H908
PublicaciónJournal of the Electrochemical Society
Volumen161
N.º14
DOI
EstadoPublicada - 2014
Publicado de forma externa

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