Selective placement of modifiers on hematite thin ... - BV FAPESP
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Selective placement of modifiers on hematite thin films for solar water splitting

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Autor(es):
Pires, Fabio A. ; dos Santos, Gabriel T. ; Bettini, Jefferson ; Costa, Carlos A. R. ; Goncalves, Renato V. ; Castro, Ricardo H. R. ; Souza, Flavio L.
Número total de Autores: 7
Tipo de documento: Artigo Científico
Fonte: SUSTAINABLE ENERGY & FUELS; v. N/A, p. 13-pg., 2023-09-07.
Resumo

The design of nanostructured materials for photoelectrochemical water splitting relies on a detailed understanding of the reactional bottlenecks. For hematite, a model system for photoanodes, the challenges concern poor charge transfer and separation, carrier recombination rate, and sluggish water oxidation kinetics. Several methods have been proposed to address each individually, with complex multi-step processes offered as solutions to improve overall performance. Here, we introduce a single polymeric precursor solution that enables the design of hematite (& alpha;-Fe2O3) with synergistic bulk and interfacial engineering using Ga3+, Hf4+ and NiFeOx. The solution causes Ga3+ to dope hematite lattice to reduce polaronic effects, while simultaneously induces Hf4+ enrichment at both surface and grain boundaries, improving charge separation and reducing recombination. Hf4+ also led to a refined microstructure derived from interface stabilization, which associated with Ga3+ bulk doping and NiFeOx electrodeposition resulted in a thin film with 65% of overall photoelectrode efficiency. As a consequence, the modified hematite photoanode (176 nm-thick) delivered a water oxidation photocurrent of 2.30 mA cm-2 in contrast to 0.37 mA cm-2 for the pristine system measured at 1.23 V against hydrogen reversible electrode (RHE). The results suggest the simplicity of this new polymeric solution may offer a cost-effective, scalable and versatile alternative for multiple chemical modifications in oxides beyond hematite. A dual-modification strategy enabling the design of hematite with synergistic bulk and interfacial engineering for improved performance as photoanode. (AU)

Processo FAPESP: 17/11986-5 - Geração e Armazenamento de Novas Energias: trazendo desenvolvimento tecnológico para o país
Beneficiário:Ana Flávia Nogueira
Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
Processo FAPESP: 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte
Beneficiário:Adalberto Fazzio
Modalidade de apoio: Auxílio à Pesquisa - Temático
Processo FAPESP: 22/04150-6 - Estudo de nanocerâmicas para aplicação em energia: sinterização e interfaces
Beneficiário:Flavio Leandro de Souza
Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
Processo FAPESP: 21/04967-0 - Síntese de fotoeletrodo de hematita por meio de rotas químicas para aplicação na quebra da molécula de água induzida pela luz solar
Beneficiário:Fabio Augusto Pires
Modalidade de apoio: Bolsas no Brasil - Doutorado Direto