Eu^III and Tb^III upconversion intermediated by interparticle energy transfer in functionalized NaLnF₄ nanoparticles

Autor(es)

Coelho, Sergio Fernando Nunes ; Bispo-Jr, Airton Germano ; de Oliveira, Nagyla Alves ; Mazali, Italo Odone ; Sigoli, Fernando Aparecido

• Tipo de documento: Artigo Científico
• Fonte: NANOSCALE; v. 16, n. 15, p. 11-pg., 2024-03-05.

Resumo

Lanthanide (Ln(III))-doped sodium gadolinium tetrafluoride (NaGdF4) nanoparticles have been excelled as attractive upconversion systems for anti-counterfeiting or energy conversion for instance, with a special interest in the visible upconversion of Eu-III and Tb-III. The core@shell architecture has enabled the bright upconversion of Eu-III and Tb-III in this matrix by interfacial energy transfer sensibilized by the Tm-III/Yb-III pair. Another approach to enable Eu-III and Tb-III upconversion could be the interparticle energy transfer (IPET) between Ln(III)-doped sensitizer and acceptor nanoparticles. Yet, the low molar absorptivity of the Ln(III) through 4f <-> 4f electronic transitions and the large distance between the nanoparticles are shortcomings that should decrease the energy transfer efficiency. On the other hand, it is feasible to predict that the association of organic ligands displaying large molar absorptivity on the acceptor nanoparticle surface could help to overcome the absorption limitation. Inspired by this exciting possibility, herein, we present the Eu-III/Tb-III upconversion intermediated by IPET between the donor Tm-III, Yb-III-doped NaGdF4 nanoparticle and the acceptor Ln(III)-doped NaGdF4 (Ln = Eu and/or Tb) nanoparticles functionalized with a series organic ligands on the surface (tta(-) = thenoyltrifluoroacetonate, acac(-) = acetylacetonate, or 3,5-bbza(-) = 3,5-dibromebenzoate). Either in solid state or in suspension, upon excitation at 980 nm, visible Eu-III/Tb-III upconversion could be observed. This emission comes from the absorption of the Tm-III, Yb-III pair in the donor nanoparticle, followed by IPET from the Tm-III excited levels to the ligand singlet/triplet states on the acceptor nanoparticle surface, ligand-to-Eu-III/Tb-III energy transfer, and upconversion emission. Spectroscopic evidences from the analysis of the donor level lifetimes indicate the contribution of non-radiative energy transfer for the IPET mechanism; the radiative mechanism also contributes for the IPET. Moreover, the design herein introduced enables the development of luminescence temperature probes with relative thermal sensitivity as high as 1.67% K-1 at 373 K. Therefore, this new upconversion pathway opens an avenue of possibilities in an uncharted territory to tune the visible upconversion of Ln(III) ions. (AU)

• Processo FAPESP: 14/25770-6 - Novas fronteiras em reações de acoplamento cruzado mediadas por paládio: associando catálise enantiosseletiva, ativações C-H, novos materiais e reações em fluxo visando alta eficiência e sustentabilidade em processos sintéticos
• Beneficiário: Carlos Roque Duarte Correia
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/02614-0 - Silicatos emissores de luz branca dopados com lantanídeos e metais de transição para aplicação em diodos emissores de luz branca quente
• Beneficiário: Marian Rosaly Davolos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/06326-1 - Luminescência de íons lantanídeos: uma ferramenta óptica contra falsificações
• Beneficiário: Fernando Aparecido Sigoli
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50906-9 - INCT 2014: em Materiais Complexos Funcionais (INOMAT)
• Beneficiário: Fernando Galembeck
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 21/08111-2 - Materiais conversores de luz à base de terras raras: marcadores luminescentes, sensores e amplificadores ópticos
• Beneficiário: Hermi Felinto de Brito
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 23/00383-9 - Reações de Heck-Matsuda enantiosseletivas autossustentadas via sais de diazônio gerados in situ a partir de anilinas ou nitroarenos em estratégias in-tandem ou one-pot cascade
• Beneficiário: Carlos Roque Duarte Correia
• Modalidade de apoio: Auxílio à Pesquisa - Regular