UV-VIS Spectroscopy/Photoluminescence for Characterization of Silica Coated Core-shell Nanomaterials

2013 ◽  
pp. 431-452 ◽  
Author(s):  
Masih Darbandi
Keyword(s):  
Core Shell ◽  
Vis Spectroscopy

scholarly journals Synthesis and characterization of noble metal–titania core–shell nanostructures with tunable shell thickness

2017 ◽  
Vol 8 ◽  
pp. 2083-2093 ◽  
Author(s):  
Bartosz Bartosewicz ◽  
Marta Michalska-Domańska ◽  
Malwina Liszewska ◽  
Dariusz Zasada ◽  
Bartłomiej J Jankiewicz
Keyword(s):  
Noble Metal ◽  
Shell Thickness ◽  
Noble Metal Nanoparticles ◽  
Core Shell ◽  
Shell Nanostructures ◽  
Vis Spectroscopy ◽  
Metal Metal ◽  
Coating Method ◽  
Titania Coating

Core–shell nanostructures have found applications in many fields, including surface enhanced spectroscopy, catalysis and solar cells. Titania-coated noble metal nanoparticles, which combine the surface plasmon resonance properties of the core and the photoactivity of the shell, have great potential for these applications. However, the controllable synthesis of such nanostructures remains a challenge due to the high reactivity of titania precursors. Hence, a simple titania coating method that would allow better control over the shell formation is desired. A sol–gel based titania coating method, which allows control over the shell thickness, was developed and applied to the synthesis of Ag@TiO2 and Au@TiO2 with various shell thicknesses. The morphology of the synthesized structures was investigated using scanning electron microscopy (SEM). Their sizes and shell thicknesses were determined using tunable resistive pulse sensing (TRPS) technique. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag@TiO2 and Au@TiO2 structures with shell thickness in the range of ≈40–70 nm and 90 nm, for the Ag and Au nanostructures respectively, were prepared using a method we developed and adapted, consisting of a change in the titania precursor concentration. The synthesized nanostructures exhibited significant absorption in the UV–vis range. The TRPS technique was shown to be a very useful tool for the characterization of metal–metal oxide core–shell nanostructures.

Synthesis and Characterization of Silica-Lead Sulfide Core Shell Nanospheres For Applications in Optoelectronic Devices

2021 ◽  
Author(s):  
Anderson Klay Romero-Jaime ◽  
Milka del Carmen Acosta-Enríquez ◽  
Diana Vargas-Hernández ◽  
Judith Celina Tánori-Córdova ◽  
Horacio Antolín Pineda-León ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Lead Sulfide ◽  
Photoelectron Spectroscopy ◽  
Core Shell ◽  
Shell System ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Spectrum Shift

Abstract Nanoscale miniaturization of chalcogenides semiconductors, such as lead sulfide (galena), can generate interesting quantum confinement effects in the field of optoelectronic applications. At this work, a process in order to obtain SiO2 nanospheres coated with Galena, as the denominated core-shell system, is developed, this process it is based in Stöber’s method, where only the magnetic stirring was replaced by an ultrasonic bath, to achieve well rounded, and highly stable silica nanoparticles with diameters average of 70 nm. The PbS shell cover presents a thickness of 10 nm around. Nanostructures chemical composition, morphology and optical properties were determined by Transmission Electron Microscopy and UV-Vis spectroscopy, respectively. As a result, the nano shells correspond to cubic PbS, presenting some interplanar distances of 2.95 Å and 3.41 Å; this nano shell also shown a toward blue optical spectrum shift and a remarkable increase in its band gap, 3.75 eV, was obtained, compared with the PbS bulk value. The chemical composition it is studied by energy scattering spectroscopy, and X-ray photoelectron spectroscopy analyzes.

scholarly journals Synthesis, Fabrication, and Characterization of Functionalized Polydiacetylene Containing Cellulose Nanofibrous Composites for Colorimetric Sensing of Organophosphate Compounds

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1869
Author(s):  
A K M Mashud Alam ◽  
Donovan Jenks ◽  
George A. Kraus ◽  
Chunhui Xiang
Keyword(s):  
Solid State ◽  
Hydroxyl Groups ◽  
Colorimetric Sensing ◽  
Electrospinning Technique ◽  
Hazardous Chemical ◽  
Tensile Tester ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Landmark Study

Organophosphate (OP) compounds, a family of highly hazardous chemical compounds included in nerve agents and pesticides, have been linked to more than 250,000 annual deaths connected to various chronic diseases. However, a solid-state sensing system that is able to be integrated into a clothing system is rare in the literature. This study aims to develop a nanofiber-based solid-state polymeric material as a soft sensor to detect OP compounds present in the environment. Esters of polydiacetylene were synthesized and incorporated into a cellulose acetate nanocomposite fibrous assembly developed with an electrospinning technique, which was then hydrolyzed to generate more hydroxyl groups for OP binding. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), Instron® tensile tester, contact angle analyzer, and UV–Vis spectroscopy were employed for characterizations. Upon hydrolysis, polydiacetylene esters in the cellulosic fiber matrix were found unaffected by hydrolysis treatment, which made the composites suitable for OP sensing. Furthermore, the nanofibrous (NF) composites exhibited tensile properties suitable to be used as a textile material. Finally, the NF composites exhibited colorimetric sensing of OP, which is visible to the naked eye. This research is a landmark study toward the development of OP sensing in a protective clothing system.

scholarly journals Structural and chemical characterization of MoO2/MoS2 triple-hybrid materials using electron microscopy in up to three dimensions

2021 ◽  
Author(s):  
Anna Frank ◽  
Thomas Gänsler ◽  
Stefan Hieke ◽  
Simon Fleischmann ◽  
Samantha Husmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Characterization ◽  
Three Dimensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Carbon Nanotube Network ◽  
Core Shell Nanoparticles

This work presents the synthesis of MoO2/MoS2 core/shell nanoparticles within a carbon nanotube network and their detailed electron microscopy investigation in up to three dimensions. The triple-hybrid core/shell material was...

scholarly journals Synthesis and characterization of silica–lead sulfide core–shell nanospheres for applications in optoelectronic devices

2021 ◽  
Author(s):  
A. K. Romero-Jaime ◽  
M. C. Acosta-Enríquez ◽  
D. Vargas-Hernández ◽  
J. C. Tánori-Córdova ◽  
H. A. Pineda León ◽  
...  
Keyword(s):  
Lead Sulfide ◽  
Optoelectronic Devices ◽  
Synthesis And Characterization ◽  
Core Shell

scholarly journals Formation and characterization of core-shell CL-20/TNT composite prepared by spray-drying technique

2021 ◽  
Author(s):  
Chang-gui Song ◽  
Xiao-dong Li ◽  
Yue Yang ◽  
Hui-min Liu ◽  
Ying-xin Tan ◽  
...  
Keyword(s):  
Spray Drying ◽  
Core Shell
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