Research Regarding a Correlation Core–Shell Morphology–Thermal Stability of Silica–Silver Nanoparticles

Postolache, Paraschiva; Petrescu, Valentin; Dumitraşcu, Dănuţ Dumitru; Rîmbu, C.; Vrînceanu, Narcisa; Cipăian, Călin Remus

doi:10.1080/00986445.2015.1078795

Cited by 5 publications

(3 citation statements)

References 44 publications

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“…A study conducted by Ghosh and Paria supporting our argument on the dependency of nanoshell thickness by the reaction concentration [27]. Another study by Postolache and co-workers [28] suggested that the increase of silver nitrate concentration effectively promotes the distribution of Ag-Nps onto the surface of SiO 2 . In addition, there are no Ag-Nps residuals was observed, which indicates a stable Ag-Nps attachment to the SiO 2 spheres.…”

Section: Uv-visible Analysissupporting

confidence: 73%

Synthesis and Characterization of Silica-Silver Core-Shell Nanoparticles

2019

MJAS

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Silica-silver core-shell nanoparticles have received tremendous interests in various applications compared to the bare silver nanoparticles due to several important features such as exhibit higher surface area, the existence of a synergistic effect between the core and the shell, stabilize silver nanoparticles against aggregation, and easily control their properties by the changing shell structure and shell geometry. Due to this significance, this study was conducted to synthesis and characterization of silica-silver core-shell nanoparticles using the facile method without any surface modification needed. In the synthesis route, silica particles have been synthesis based on the Stӧber method. The deposition of nanoscales silver layer on silica surface mainly involves the electrostatic attraction between [Ag(NH 3 ) 2 ] + ions and silanol groups, and the addition of polyvinylpyrrolidone (PVP) has been acted as a reducing agent and stabilizing agent. UV-Vis spectroscopy evidenced the absorption of surface plasmon resonance (SPR) of silver nanoparticles in the range 380-450 nm. The crystallinity of silica-silver core-shell nanoparticles showed the facecentered cubic (fcc) structure by X-ray powder diffraction (XRD) analysis. The spherical shape of silica particles with an average 200-220 nm in size has been determined using scanning electron microscope (SEM). The high resolution-transmission electron microscope (HR-TEM) images visualized the successful formation of spherical silver nanoparticles on the silica surface with the average of size 10-40 nm. X-ray photoelectron spectroscopy analysis revealed the elemental compositions exist in the silica-silver core-shell nanoparticles. The synthesized silica-silver core-shell nanoparticles will be used as a potential catalyst in dye treatment application in the future work.

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Section: Uv-visible Analysissupporting

confidence: 73%

Synthesis and Characterization of Silica-Silver Core-Shell Nanoparticles

2019

MJAS

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“…Figure D shows FTIR spectra of the four NP types used in the present work. The central feature of the spectra of the SiO 2 NPs as well as the PNPs are the peaks related to the SiO 2 matrix at ∼1100, 800, and 460 cm –1 . − The second most prominent peak is the one at ∼3432 cm –1 assigned to the OH groups of the surficial silanols − (see also Table S1 in the Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Reversible Plasmonic Switch in a Molecular Oxidation Catalysis Process

et al. 2022

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Currently, plasmonic nanoparticles (PNPs) are considered highly efficient enhancers of catalytic processes. Herein, we report a concept where plasmonic Ag0@SiO2 nanoparticles can reversibly switch-off an oxidation catalytic process under light-excitation. The catalytic process recommences when illumination is stopped. The catalytic system under study is a well-characterized molecular LMnII catalyst that performs alkene oxidation, with H2O2 as the oxidant. Three types of plasmonic core–shell Ag0@SiO2 nanoparticles, with a SiO2 shell of varying thickness (0.1–5 nm), were utilized in this study. Using electron paramagnetic resonance spectroscopy, we have identified the reversible inhibition of the transient LMnIVO intermediate formation, to be the key-step of the photoinduced pause of the catalytic process by the Ag0@SiO2 PNPs. Surface-enhanced Raman spectroscopy (SERS) and redox potential data show that the plasmonic Ag0@SiO2 NPs exert a moderate SERS effect on the LMnII catalyst, and a considerable lowering of the solution redox potential E h. Our data show that near-field generation is not the sole origin of inhibition of LMnIVO formation, while plasmonic heating was insignificant. We suggest that the generation of hot electrons by the Ag0@SiO2 PNPs is implicated, along with near-field generation, in the reversible switch-off of the catalytic process.

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“…In this context, a new release law, independent of the polymer matrix and/or drug types, is deducted and validated by the experimental data from the literature. Thereby, also the behavior of biological structures is explained, with a high nonlinear character, under the action of drug delivery systems [ 20 – 27 ].…”

Section: Discussionmentioning

confidence: 99%