Band Gap Narrowing of Bi-Doped NaTaO3 for Photocatalytic Hydrogen Evolution under Simulated Sunlight: A Pseudocubic Phase Induced by Doping

Autor(es)

Alves, Gustavo A. S. ^[1] ; Centurion, Higor A. ^[1] ; Sambrano, Julio R. ^[2] ; Ferrer, Mateus M. ^[3] ; Goncalves, V, Renato

Afiliação do(s) autor(es)

^[1] V, Univ Sao Paulo, Sao Carlos Inst Phys, BR-13560970 Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ, Modeling & Mol Simulat Grp, BR-17030360 Bauru, SP - Brazil

^[3] Univ Fed Pelotas, CCAF, PPGCEM CDTec, BR-96010610 Pelotas, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACS APPLIED ENERGY MATERIALS; v. 4, n. 1, p. 671-679, JAN 25 2021.
• Citações Web of Science: 0

Resumo

NaTaO3 is a promising material for the production of hydrogen fuel via photocatalytic water splitting, although the wide band gap prevents its application with solar light. In order to overcome this issue, bismuth doping has been proposed as a method for band gap narrowing by introducing midgap electron states. In this work, Bi-doped NaTaO3 nanocubes were synthesized through a facile molten salt method and the photocatalysts exhibit hydrogen evolution under simulated sunlight irradiation (AM 1.5G). X-ray diffraction, Raman, and UV-vis spectra suggest that the incorporation of Bi3+ at the Ta-site induces band gap narrowing, in addition to a structural transition, as the orthorhombic perovskite lattice becomes pseudocubic at low dopant concentrations (0.5-4 mol %). The optimal photocatalytic activity of 3 mol % Bi-doped NaTaO3 may be a result of the simultaneous presence of the pseudocubic lattice and the narrowed band gap of 3.6 eV, which in turn promote the absorption of ultraviolet light from the AM 1.5G irradiation source. Theoretical simulations based on density functional theory were used in conjunction with the experimental results to present in detail the additional contribution of the doped pseudocubic phase in the system. Furthermore, 3 mol % Bi-doped NaTaO3 was loaded with Ni cocatalysts by magnetron sputtering deposition, leading to enhanced and stable H-2 production rates for more than 100 h of reaction. (AU)

• Processo FAPESP: 19/08928-9 - Modelagem e Simulações da Funcionalização de Nanotubos Porosos Inorgânicos
• Beneficiário: Julio Ricardo Sambrano
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/25705-0 - Estudo das junções NaTaO3/Fe2TiO5 e NaTaO3/WO3 para a formação de sistemas tandem para a produção de hidrogênio a partir da água e luz solar
• Beneficiário: Gustavo Andrade Silva Alves
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 17/18716-3 - Fotossíntese artificial: desenvolvimento de sistemas Tandem para a produção de hidrogênio combustível a partir da água e luz solar
• Beneficiário: Renato Vitalino Gonçalves
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores