Improving the stability of plasmonic magnesium nanoparticles in aqueous media

The strategy of anchoring molecular catalysts on electrode surfaces combines the high selectivity and activity of molecular systems with the practicality of heterogeneous systems. The stability of molecular catalysts is, however, far less than that of traditional heterogeneous electrocatalysts, and therefore a method to easily replace anchored molecular catalysts that have degraded could make such electrosynthetic systems more attractive. Here, we apply a non-covalent “click” chemistry approach to reversibly bind molecular electrocatalysts to electrode surfaces via host-guest complexation with surface-anchored cyclodextrins. The host-guest interaction is remarkably strong and allows the flow of electrons between the electrode and the guest catalyst. Electrosynthesis in both organic and aqueous media was demonstrated on metal oxide electrodes, with stability on the order of hours. The catalytic surfaces can be recycled by controlled release of the guest from the host cavities and readsorption of fresh guest. This strategy represents a new approach to practical molecular-based catalytic systems.

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On the Structure of Lead(II) Complexes in Aqueous Solutions. I. Trinuclear Clusters

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19950527 ◽

1995 ◽

Vol 60 (4) ◽

pp. 527-536 ◽

Cited By ~ 10

Author(s):

Martin Breza ◽

Alena Manová

Keyword(s):

Quantum Chemistry ◽

Aqueous Solutions ◽

Electronic Structures ◽

Mndo Method ◽

Model Systems ◽

Trinuclear Clusters ◽

The Stability ◽

Semiempirical Mndo

Using semiempirical MNDO method of quantum chemistry the optimal geometries and corresponding electronic structures of [Pb3(OH)n]6-n model systems as well as of their hydrated [Pb3(OH)n(H2O)8-n]6-n analogues (n = 4, 5) are investigated. The most stable trinuclear lead(II) complexes present in aqueous solutions correspond to cyclo-(μ3-OH)(μ2-OH)3Pb32+, Pb(μ-OH)2Pb(μ-OH)2Pb2+, cyclo-(μ3-OH)2(μ2-OH)3Pb3+, Pb(OH)(μ-OH)2Pb(μ-OH)Pb(OH)+ and Pb(OH)(μ-OH)2Pb(μ-OH)2Pb+ systems. The key role of OH bridges (by vanishing direct Pb-Pb bonds) on the stability of individual isomers is discussed.

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Numerical Study on the Surface Plasmon Resonance Tunability of Spherical and Non-Spherical Core-Shell Dimer Nanostructures

Nanomaterials ◽

10.3390/nano11071728 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1728

Author(s):

Joshua Fernandes ◽

Sangmo Kang

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Surface Plasmon Resonance ◽

Aspect Ratio ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Shell Thickness ◽

Numerical Study ◽

Field Enhancement ◽

Core Shell

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.

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The effect of shell thickness on gas sensing properties of core-shell fibers

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2021.129456 ◽

2021 ◽

Vol 332 ◽

pp. 129456

Author(s):

Ming Zhang ◽

Ning Sui ◽

Rui Wang ◽

Tong Zhang

Keyword(s):

Shell Thickness ◽

Gas Sensing ◽

Core Shell ◽

Sensing Properties ◽

Gas Sensing Properties

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Highly fluorescent CsPbBr3/TiO2 core/shell perovskite nanocrystals with excellent stability

SN Applied Sciences ◽

10.1007/s42452-021-04648-8 ◽

2021 ◽

Vol 3 (6) ◽

Author(s):

Haitao Chen ◽

Renhua Li ◽

Anqi Guo ◽

Yu Xia

Keyword(s):

Identical Particle ◽

Core Shell ◽

List Type ◽

Easy Method ◽

Time Resolved ◽

Perovskite Nanocrystals ◽

Promising Application ◽

The Stability ◽

Time Resolved Photoluminescence ◽

Excellent Stability

AbstractThe poor stability of CsPbX3 (X = Cl, Br, I) perovskite nanocrystals is the most impediment to its application in the field of photoelectrics. In this work, monodisperse CsPbBr3/TiO2 nanocrystals are successfully prepared by coating titanium precursor on the surface of colloidal CsPbBr3 nanocrystals at room temperature. The CsPbBr3/TiO2 nanocomposites exhibit excellent stability, remaining the identical particle size (9.2 nm), crystal structures and optical properties. Time-resolved photoluminescence decay shows that the lifetime of CsPbBr3/TiO2 nanocrystals is about 4.04 ns and keeps great stability after lasting two months in the air. Results show that the coating of TiO2 on CsPbBr3 NCs greatly suppressed the anion exchange and photodegradation, which are the main reasons for dramatically improving their chemical stability and photostability. The results provide an effective method to solve the stability problem of perovskite nanostructures and are expected to have a promising application in optoelectronic fieldsArticle highlights 1. Prepared the all-inorganic CsPbBr3/TiO2 core/shell perovskite nanocrystals by an easy method. 2. Explored its essences of PL and lifetime of the synthesized CsPbBr3/TiO2 perovskite nanocrystals. 3. CsPbBr3/TiO2 nanocrystals show the great thermal stability after the post-annealing. 4. The CsPbBr3/TiO2 nanocrystals have a high PLQY and have a promising application in solar cells.

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Effective replacement of cetyltrimethylammonium bromide (CTAB) by mercaptoalkanoic acids on gold nanorod (AuNR) surfaces in aqueous solutions

Nanoscale ◽

10.1039/c9nr09137h ◽

2020 ◽

Vol 12 (2) ◽

pp. 658-668 ◽

Cited By ~ 6

Author(s):

Rafael del Caño ◽

Jose M. Gisbert-González ◽

Jose González-Rodríguez ◽

Guadalupe Sánchez-Obrero ◽

Rafael Madueño ◽

...

Keyword(s):

Aqueous Solutions ◽

Gold Nanorods ◽

Ligand Exchange ◽

Cetyltrimethylammonium Bromide ◽

Gold Nanorod ◽

Experimental Conditions ◽

Seed Mediated ◽

The Stability

The highly packed cetyltrimethylammonium bromide bilayer on the surface of gold nanorods synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions.

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Investigations of ternary complexes of Co(II) and Ni(II) with thiodiacetate anion and 1,10-phenanthroline or 2,2’-bipyridine in aqueous solutions

Open Chemistry ◽

10.1515/chem-2015-0048 ◽

2014 ◽

Vol 13 (1) ◽

Author(s):

Dariusz Wyrzykowski ◽

Joanna Pranczk ◽

Dagmara Jacewicz ◽

Aleksandra Tesmar ◽

Bogusław Pilarski ◽

...

Keyword(s):

Aqueous Solutions ◽

Substitution Reactions ◽

Experimental Conditions ◽

Kinetic Measurements ◽

Hydroxo Complexes ◽

Binary Complexes ◽

Vis Spectroscopy ◽

Potentiometric Titration Method ◽

The Stability ◽

Ph Range

AbstractA potentiometric titration method (PT) and a stopped-flow kinetic technique monitored by a UV−Vis spectroscopy have been used to characterize the stability of series of Co(II)- and Ni(II)-thiodiacetato complexes, M(TDA), in the presence of 1,10-phenanthroline (phen) or 2,2’-bipyridine (bipy) in aqueous solutions. The stability constants of the binary (1:1), ternary (1:1:1) as well as the resulting hydroxo complexes were evaluated and compared to the corresponding oxydiacetate complexes. Based on the species distribution as a function of pH the relative predominance of the species in the system over a pH range was discussed. Furthermore, the kinetic measurements of the substitution reactions of the aqua ligands to phen or bipy in the coordination sphere of the binary complexes M(TDA) were performed in the 288–303 K temperature range, at a constant concentration of phen or bipy and at seven different concentrations of the binary complexes (0.2–0.5 mM). The kinetic stability of the M(TDA) complexes was discussed in relation to the experimental conditions and the kind of the auxiliary ligands (phen/bipy). Moreover, the influence of the type of primary ligand (thiodiacetate/oxydiacetate) on the substitution rate of the auxiliary ligands was also compared.

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Addition of Aliphatic and Aromatic Amines to Catechol in Aqueous Solution Under Oxidizing Conditions

Australian Journal of Chemistry ◽

10.1071/ch9890365 ◽

1989 ◽

Vol 42 (3) ◽

pp. 365 ◽

Cited By ~ 15

Author(s):

MK Manthey ◽

SG Pyne ◽

RJW Truscott

Keyword(s):

Aqueous Solution ◽

Aqueous Solutions ◽

Aromatic Amines ◽

Aliphatic Amines ◽

Substitution Pattern ◽

Vinylogous Amides ◽

The Stability

The oxidation of catechol in the presence of two aliphatic and aromatic amines has been investigated. In aqueous solutions of pH 7.0 and 11.7, the substitution pattern of the adduct was dependent on the type of amine used. Aromatic amines produced 4,5-disubstituted o-quinones, whereas aliphatic amines gave either 2,4,5-trisubstituted or 2,4-disubstituted o-quinone adducts. A rationale based upon the stability of vinylogous amides is presented to account for the observed substitution pattern.

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Optical Temperature Sensing of Core-Shell Structured NaYF4:Yb3+, Er3+@NaYF4 Nanocrystals with Different Shell Thickness

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.738-739.27 ◽

2015 ◽

Vol 738-739 ◽

pp. 27-30

Author(s):

Dong Dong Li ◽

Qi Yue Shao ◽

Yan Dong ◽

Jian Qing Jiang

Keyword(s):

Shell Thickness ◽

Thermal Sensitivity ◽

Upconversion Luminescence ◽

Temperature Sensing ◽

Upconversion Nanoparticles ◽

Core Shell ◽

Sensing Properties ◽

The Core ◽

Β Phase ◽

Biomedical Fields

Hexagonal (β)-phase NaYF4:Yb3+, Er3+ upconversion nanoparticles (UCNPs) with and without an inert (undoped NaYF4) shell have been successfully synthesized and the effects of shell thickness on the upconversion luminescence (UCL) and temperature sensing properties were systematically investigated. It was found that the NaYF4 shell and its thickness do not affect the RHS values and thermal sensitivity, but can obviously improve the UCL intensity of NaYF4:Yb3+, Er3+ UCNPs. It implies that the core-shell structured NaYF4:Yb3+, Er3+@NaYF4 UCNPs with excellent UCL properties have great potential to be used as temperature sensing probes in biomedical fields, without considering the influences of the shell thickness on their temperature sensing properties.

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