Highly oriented hematite nanorods arrays for photoelectrochemical water splitting

Autor(es)

de Carvalho, Vitor A. N. ^[1] ; Luz, Roberto A. de S. ^[1] ; Lima, Bruno H. ^[2] ; Crespilho, Frank N. ^{[3, 1]} ; Leite, Edson R. ^[2] ; Souza, Flavio L. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, Grp Mat & Metodos Avancados, BR-09090400 Santo Andre, SP - Brazil

^[2] PPGCEM Univ Fed Sao Carlos, BR-13565905 Sao Carlos, SP - Brazil

^[3] Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Power Sources; v. 205, p. 525-529, MAY 1 2012.
• Citações Web of Science: 50

Resumo

We report an oriented hematite undoped photanode synthesized by single chemical route step at low temperature and with a short reaction time. Fluorine-doped tin oxide (FTO) electrodes modified with hematite nanorod (450 nm of thickness) showed a photocurrent with 0.9 mA cm(-2) at 0.4 V vs Ag/AgCl. Also, we have done electrochemical characterizations under dark conditions in order to understand the catalytic properties of the photoanode. Based on cyclic voltammetry results we have proposed a new mechanism to explain the evolution of molecular oxygen onto oriented hematite surfaces, in which is not inconsistent with thermodynamical parameters extracted from the Pourbaix diagram. A chemical interaction between OH- and iron oxide from the surface suggested that the chemical reaction is first governed by oxy-hydroxides on the electrode/electrolyte interface. In other word, molecular oxygen evolution is preceded by the formation of oxy-hydroxide groups, a slow and possibly limiting step. (C) 2012 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/15558-1 - Interação entre biomoléculas e sistemas celulares com nanoestruturas 0D, 1D e 2D utilizando métodos eletroquímicos
• Beneficiário: Frank Nelson Crespilho
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/02464-6 - Estudo de nanoestruturas de óxidos metálicos aplicados a células fotovoltaicas
• Beneficiário: Flavio Leandro de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/01541-0 - Desenvolvimento de bioanodos constituídos por glicose oxidase e frutose desidrogenase e suas formas recombinantes para aplicação em protótipos de biocélulas a combustível enzimáticas: geração de energia a partir da biomassa (cana-de-açúcar)
• Beneficiário: Frank Nelson Crespilho
• Modalidade de apoio: Auxílio à Pesquisa - Regular