Photoelectrochemical Oxygen Evolution on Mesoporous Hematite Films Prepared from Maghemite Nanoparticles

Autor(es)

Verissimo, N. C. ; Ren, D. ; Kleiner, C. C. C. ; Hesse, F. A. B. ; Zakeeruddin, S. M. ; Graetzel, M. ; Bertazzoli, R.

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Electrochemical Society; v. 169, n. 5, p. 9-pg., 2022-05-01.

Resumo

Iron oxides, especially hematite (alpha-Fe2O3), a are promising materials for applications in photoelectrochemical cells and photo-redox catalysis. However, realizing high-performance hematite photoanodes via an environmentally-friendly route remains a great challenge. In this work, we employed a novel approach to prepare mesoscopic hematite photoelectrodes with remarkable performance for water oxidation. Hydrothermally-synthesized maghemite nanoparticles of high crystallinity with a mean particle size of 3.3 nm were deposited onto fluorine doped tin oxide (FTO) transparent conducting glass substrates, followed by heat treatment to convert them into a homogeneous mesoporous hematite layer. A hematite photoanode with a thickness of 220 nm, delivered a maximum photocurrent density of 1.8 mA cm(-2) for water oxidation to oxygen at 1.23 V-RHE under simulated AM 1.5 irradiation. Upon treating the surface of the hematite photoelectrode with Co(II) cations the photocurrent density nearly doubled at the same potential to 3.32 mA cm(-2) placing our new photoelectrode among the best hematite-based photocatalysts for visible light induced water splitting. Further photoelectrochemical analysis provided insights into the factors boosting the performance of the hematite photoanode. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited. (AU)

• Processo FAPESP: 18/13243-2 - Síntese e caracterização de filmes de fotocatalisadores nanoestruturados de TiO2@±-Fe2O3 depositados por InkJet-Printing: aplicação na decomposição de compostos orgânicos benzoadiazepínicos"
• Beneficiário: Nathália Carolina Verissimo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/26005-5 - Síntese e caracterização de eletrodos a base de hematita de alta performance para separação da água por fotoeletroquímica
• Beneficiário: Nathália Carolina Verissimo
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado