Determination and Optimization of the Luminescence External Quantum Efficiency of Silver-Clusters Zeolite Composites

Coutiño-González, Eduardo; Roeffaers, Maarten B. J.; Dieu, Bjorn; Cremer, Gert De; Leyre, Sven; Hanselaer, Peter; Fyen, Wim; Sels, Bert F.; Hofkens, Johan

doi:10.1021/jp400511z

Cited by 66 publications

(110 citation statements)

References 47 publications

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“…Obviously, there are many other possible cluster species, such as Ag 4 2+ , which are not emissive, and therefore not being detected. 40 Only after dehydration, fluorescence is observed due to the formation of silver clusters. First, the observation of the Ag n + clusters in the time frame of hours is unusual, since in solution, the rate constant for coalescence of silver clusters is ~ 4 x 10 8 l mol -1 s -1 .…”

Section: Acs Paragon Plus Environmentmentioning

confidence: 99%

Evolution of Silver Nanoparticles within an Aqueous Dispersion of Nanosized Zeolite Y: Mechanism and Applications

Severance

Dutta

2014

J. Phys. Chem. C

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Stable aqueous dispersion of silver ion-exchanged nanozeolite Y was reacted with the three common dihydroxyphenols, hydroquinone, catechol and resorcinol. With hydroquinone and catechol, there was rapid reduction of the intrazeolitic silver to form metallic silver with complete destruction of the zeolite framework. Resorcinol, the weakest reducing agent amongst the group behaved differently. The formation of metallic silver was considerably slower, and the zeolite framework was mostly intact. This made it possible to examine the evolution of silver cluster formation with optical spectroscopy and transmission electron microscopy. In the first 135 min of reaction, extinction/fluorescence spectroscopy indicates the formation of Ag n<4 and Ag n>4 clusters. The smaller clusters disappear more rapidly with time. For the 1 hr reduced sample, transmission electron microscopy showed uniform distribution of 1.4 nm Ag particles throughout the zeolite.After 2 hr of reduction, the average size of the particles was 2.5 nm, and a fraction of these particles appeared on the zeolite surface. With further time of reduction (3-24 hr), more of the intrazeolitic Ag migrated to the surface, and Ostwald ripening into larger nanoparticles (> 3 nm) was observed at the zeolite-solution interface. We propose that the slow growth of the silver prevented the destruction of the zeolite framework. Two factors are considered important for the slow growth of silver with resorcinol. First, resorcinol is a weak reducing agent. Second, and more importantly, the intrazeolitic pH drops upon initial silver reduction, as measured by an acidochromic dye, which raises the reduction potential of resorcinol, thereby arresting further reduction and particle growth. By removing the resorcinol at any stage of the reduction, stable Ag nanoparticles on nanozeolite samples can be isolated. Such samples were investigated as SERS substrates as well as a heterogeneous

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Section: Acs Paragon Plus Environmentmentioning

confidence: 99%

Evolution of Silver Nanoparticles within an Aqueous Dispersion of Nanosized Zeolite Y: Mechanism and Applications

Severance

Dutta

2014

J. Phys. Chem. C

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“…For instance, zeolite-Y are utilized as excellent hosts for luminescent materials because of their strong ability of separating the luminescent centers, thus, reducing the concentration quenching23. Therefore, it provides a superb chemical environment for luminescent centers due to its outstanding thermal and chemical stability, such as rare earth ions456, quantum dots789101112, and noble metal Ag131415. These composite materials have potential applications in white light emitting diodes (WLEDs)16, solar cells17, optical code18, biomedicine1920 and so on.…”

mentioning

confidence: 99%

Interaction between the exchanged Mn2+ and Yb3+ ions confined in zeolite-Y and their luminescence behaviours

Sun

Xiong

et al. 2017

Sci Rep

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Luminescent zeolites exchanged with two distinct and interacted emissive ions are vital but less-studied for the potential applications in white light emitting diodes, solar cells, optical codes, biomedicine and so on. Typical transition metal ion Mn2+ and lanthanide ion Yb3+ are adopted as a case study via their characteristic transitions and the interaction between them. The option is considered with that the former with d-d transition has a large gap between the first excited state 4T1 and the ground state 6A1 (normally >17,000 cm−1) while the latter with f-f transition has no metastable excited state above 10,000 cm−1, which requires the vicinity of these two ions for energy transfer. The results of various characterizations, including BET measurement, photoluminescence spectroscopy, solid-state NMR, and X-ray absorption spectroscopy, etc., show that Yb3+ would preferably enter into the zeolite-Y pores and introduction of Mn2+ would cause aggregation of each other. Herein, cation-cation repulsion may play a significant role for the high valence of Mn2+ and Yb3+ when exchanging the original cations with +1 valence. Energy transfer phenomena between Mn2+ and Yb3+ occur only at elevated contents in the confined pores of zeolite. The research would benefit the design of zeolite composite opto-functional materials.

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“…Diffuse reflectance spectroscopy has frequently been used in the case for which this sophisticated instrumentation has been developed. 10,24 Advancing dye−ZL research requires measurements that not only yield spectra and quantum yields as numbers but also provide information useful for understanding the mechanisms behind the observed phenomena. A prerequisite for these are high quality absorption and luminescence spectra where the band shapes can be interpreted unambiguously.…”

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confidence: 99%

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

et al. 2013

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Electronic absorption and fluorescence spectra based on transmission measurements of thin layers obtained from new perylene−zeolite L composites and new dye1,dye2−zeolite L sandwich composites, the latter acting as antenna systems, have been investigated and analyzed. The influence of extra-and intraparticle self-absorption on the spectral shape and fluorescence quantum yield is discussed in detail. Due to its intraparticle origin, self-absorption and re-emission can often not be avoided in organized systems such as dye−zeolite L composites where a high density of chromophores is a prerequisite for obtaining the desired photophysical properties. We show, however, that it can be avoided or at least minimized by preparing dye1,dye2−zeolite L sandwich composites where donors are present in a much larger amount than the acceptors because they act as antenna systems. ■ INTRODUCTIONComposites synthesized by embedding molecules, complexes, and clusters into the one-dimensional channels of zeolite L (ZL) 1,2 have recently experienced increasing interest from scientists engaged in different fields, ranging from very stable nontoxic pigments to novel optical materials with a large variety of different properties to promising objects for utilization in analytics, biology, diagnostics and drug delivery. This trend is exemplified by publications that appeared in 2013. 3−16 Electronic absorption and luminescence spectroscopy are important tools for characterizing the host−guest composites, and luminescence is often one of their key properties. Confocal luminescence microscopy on individual crystals has successfully been used and has contributed much to our current understanding of various dye−ZL properties. 17−23 It is very often desirable to measure absorption and luminescence spectra of an ensemble in order to unambiguously interpret the observations and sometimes to derive luminescence quantum yields. Diffuse reflectance spectroscopy has frequently been used in the case for which this sophisticated instrumentation has been developed. 10,24 Advancing dye−ZL research requires measurements that not only yield spectra and quantum yields as numbers but also provide information useful for understanding the mechanisms behind the observed phenomena. A prerequisite for these are high quality absorption and luminescence spectra where the band shapes can be interpreted unambiguously. This is best guaranteed if high quality transmission spectra are available. We have therefore successfully applied refractive index matching techniques in order to reduce or in favorable cases eliminate light scattering. We have used dispersions in liquid solvents or polymers as matrixes for dye−ZL composites, where sometimes a surface modification of the ZL crystals was required.25−27 More recently, a method for the preparation of thin oil−glass sandwiches (OGS) from dye−ZL composites has been employed. 15,20 This technique has proven to be very convenient and allows differentiating between mechanisms that affect the shape of the absorptio...

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Determination and Optimization of the Luminescence External Quantum Efficiency of Silver-Clusters Zeolite Composites

Cited by 66 publications

References 47 publications

Evolution of Silver Nanoparticles within an Aqueous Dispersion of Nanosized Zeolite Y: Mechanism and Applications

Evolution of Silver Nanoparticles within an Aqueous Dispersion of Nanosized Zeolite Y: Mechanism and Applications

Interaction between the exchanged Mn2+ and Yb3+ ions confined in zeolite-Y and their luminescence behaviours

Self-Absorption and Luminescence Quantum Yields of Dye-Zeolite L Composites

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