An intensity modulated photocurrent spectroscopy study of the role of titanium in thick hematite photoanodes

Autor(es)

Rodriguez-Gutierrez, Ingrid ^{[1, 2]} ; Souza Junior, Joao B. ^[1] ; Leite, Edson R. ^{[3, 1]} ; Vayssieres, Lionel ^[4] ; Souza, Flavio L. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Nanotechnol Natl Lab LNNano, BR-13083970 Campinas - Brazil

^[2] Fed Univ ABC UFABC, Ctr Ciencias Nat & Humanas CCNH, BR-09210580 Santo Andre, SP - Brazil

^[3] Univ Fed Sao Carlos, Dept Quim, BR-13565905 Sao Carlos - Brazil

^[4] Xi An Jiao Tong Univ, Int Res Ctr Renewable Energy IRCRE, Sch Energy & Power Engn, State Key Lab Multiphase Flow Power Engn, Xian 710049 - Peoples R China

• Tipo de documento: Artigo Científico
• Fonte: Applied Physics Letters; v. 119, n. 7 AUG 16 2021.
• Citações Web of Science: 0

Resumo

In this Letter, the role of Ti addition in thick hematite mesoporous photoanodes was elucidated by performing intensity modulated photocurrent spectroscopy (IMPS) monitoring its charge carrier dynamics during water oxidation. Interface engineering associated with doping of hematite is crucial to develop highly efficient thick photoanodes. Photoelectrochemical data recorded under front- and back-side illumination show that Ti insertion mitigates the collection deficit faced by hematite due to an energy barrier decrease between the grains and a change in the surface chemistry. IMPS reveals that Ti clearly influences the hematite film performance by increasing the charge separation efficiency due to its segregation at the hematite interface. However, Ti insertion does not enhance the kinetics of water oxidation at the solid-liquid interface. These facts indicate that Ti mainly affects the hematite electronic properties instead of accelerating the surface processes. This comprehensive understanding of the electronic transport and charge carrier dynamics in Ti:hematite photoanodes enables the control and design of better interfaces for more efficient photoelectrochemical water splitting. (AU)

• Processo FAPESP: 19/06654-9 - Incorporação de nanopartículas metálicas em fotoeletrodos de hematita: efeito da interface sólido-sólido nas propriedades ópticas e elétricas
• Beneficiário: Ingrid Guadalupe Rodriguez Gutierrez
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• 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: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• 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