Preparation and Characterization of the Core/Shell Structured of CdTe/Ni Fluorescent-Magnetic Particle

2011 ◽  
Vol 217-218 ◽  
pp. 216-219 ◽  
Author(s):  
Shi Chao Xu ◽  
Yue Qian Yang ◽  
Yan Shan Liu ◽  
Heng Miao ◽  
Mei Dong ◽  
...  
Keyword(s):  
Optical Properties ◽  
Hydrazine Hydrate ◽  
Magnetic Core ◽  
Red Shift ◽  
Nano Particles ◽  
Molar Ratio ◽  
Core Shell ◽  
Ni Nanoparticles ◽  
Dna Labeling ◽  
Dual Functional

The niclel nanoparticles were prepared via polyol process with hydrazine hydrate as reductant, the optimum conditions were investigated and proposed to be the molar ratio of NiCl2: NaOH: Hydrazine hydrate =1: 2: 11, 60 °C, pH5.5. The qualified fluorescent-magnetic dual functional CdTe/Ni nanoparticles were synthesized via layer-by-layer (LBL) technique, Ni was designed to be magnetic core and CdTe was used as fluorescent shell material, the molar ratio of CdTe:Ni is 4.5:1. The morphology of the Ni nano particles and CdTe/Ni core shell dual functional nano particles were characterized by transmission electron microscopy (TEM), and optical properties were investigated with fluorescence spectrum (FS) and ultra violet spectrum (UV). The synthesized CdTe/Ni nanoparticles showed yellow fluorescence when excited at 365nm, CdTe/Ni magnetic core shell QDs can be simply precipitated with a common magnet. TEM data indicated that ~15nm of Ni nanoparticles were obtained and ~25nm of CdTe/Ni core shell dual functional nanoparticles were prepared. Red shift of maximum absorbance peak was detected via UV, and these results inferred the QDs growth, moreover, 40nm red shift of maximum emission wavelength from 530nm to 570nm was observed, and which showed the growth QDs and formation of CdTe shell. The prepared magnetic core shell CdTe/Ni nanoparticles showed excellent optical properties, and it is expected to be useful and helpful in DNA sensing based on fluorescence resonance energy transfer, biological separating, and DNA labeling process.

Synthesis, Characterization, and Optical Properties of Near-Infrared Reflecting Composite Inorganic Pigments Composed of TiO2/CuO Core–Shell Particles

2018 ◽  
Vol 71 (5) ◽  
pp. 373 ◽  
Author(s):  
Bolong Yao ◽  
Siyao Geng ◽  
Jie Wang ◽  
Likui Wang
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Near Infrared ◽  
Diffuse Reflectance Spectroscopy ◽  
Infrared Region ◽  
Molar Ratio ◽  
Core Shell ◽  
Near Infrared Reflectance ◽  
Cu Content ◽  
Solar Reflectance

Pigments with dark appearance and high solar energy reflectance are of great application value. In the present work, dark grey composite pigments with a TiO2/CuO core–shell structure were prepared through calcination of precursors obtained from the precipitation of Cu(OH)2 on TiO2 particles. The composition, structure, and optical properties of the synthesised powders were characterised by colourimetry, near-infrared diffuse reflectance spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The pigments are composed of rutile TiO2 and tenorite CuO, and the powder colour changes from white to dark grey as the Cu content increases. With a molar ratio of CuO to TiO2 of 0.6, the pigment presents optimal colour (a* = 1.66, b* = −2.19, L* = 52.37) and optical performance. The near-infrared reflectance, the solar reflectance in the near-infrared region, and the total solar reflectance reach 87.2, 70.6, and 37.2 %, respectively. Furthermore, it is demonstrated that the composite pigments exhibit a deeper colour and higher reflectivity than conventional dark-blended powders. These cool dark pigments could be applied in the coatings for buildings (roofs and walls) to improve building comfortability and reduce cooling energy consumption.

Investigation of Factors Induced the Non-Intrinsic Optical Properties for Water-Soluble CdSe Semiconductor Quantum Dots

2010 ◽  
Vol 663-665 ◽  
pp. 437-440
Author(s):  
Heng Kang Qiu ◽  
Yue Shen ◽  
Lin Jun Wang ◽  
Jian Cheng Zhang ◽  
Kai Feng Qin
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Photoelectron Spectroscopy ◽  
Semiconductor Quantum Dots ◽  
Water Soluble ◽  
Nano Particles ◽  
Crystal Nucleation ◽  
Band Edge ◽  
Molar Ratio ◽  
X Ray

For the purpose of investigating the factors induced the non-band-edge excitation optical properties of water-soluble CdSe semiconductor quantum dots (QDs), the initial molar ratio of Cd and Se(or Cd/Se), the temperature of crystal nucleation and growing, the time of the growth etc. are systematically studied in the fabricated process. The properties of the as-prepared nano-particles (NPs) have been characterized by ultraviolet-visible absorption spectra (UV-Vis), photoluminescence (PL) spectroscopy, X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The measured results show that it is possible to exist surface trapping, impurities and other defect energy states in the products with the non-band-edge excitation PL properties, and all the characteristics are involved with the different synthetic routes and prepared techniques.

Optical Properties of CdS and CdTe Sensitized ZnO Nanorods

2014 ◽  
Vol 1707 ◽  
Author(s):  
C. J. Pereyra ◽  
F. Ferrer ◽  
R. E. Marotti ◽  
C. Gómez ◽  
L. Campo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Numerical Simulations ◽  
Diffuse Reflectance ◽  
Zno Nanorods ◽  
Effective Medium ◽  
Red Shift ◽  
Band Edge ◽  
Effective Medium Approximation ◽  
Core Shell ◽  
Sensitive Dependence

ABSTRACTOptical properties of ZnO-CdTe electrochemically prepared on a core-shell nanostructure (NS) were studied. Numerical simulations based on effective medium approximation give higher absorption than ZnO-CdS samples and a sensitive dependence on CdTe content. The absorption edges for deep black samples found by transmittance (T(λ)) and diffuse reflectance (Rdiff(λ)) measurements were at 1.33eV and 1.55eV, respectively. A split-off band edge was also found by Rdiff(λ) at ∼2.5eV. The red shift observed in T(λ), previously observed in ZnO-CdS, and may confirm the enhancement of sub-bandgap absorption due to the NS nature of samples.

scholarly journals SYNTHESIS AND OPTICAL PROPERTIES OF MESOMORPHIC GLASSY NANOCOMPOSITES BASED ON CADMIUM CAPRYLATE WITH CdSe / ZnS HETERONANOPARTICLES

2019 ◽  
Vol 85 (1) ◽  
pp. 13-18
Author(s):  
Tatiana Mirnaya ◽  
Galina Yaremchuk ◽  
Alexander Kosheliev
Keyword(s):  
Optical Properties ◽  
Liquid Crystalline ◽  
Spectral Characteristics ◽  
Fluorescence Band ◽  
Molar Ratio ◽  
Emission Region ◽  
Core Shell ◽  
Zns Nanoparticles ◽  
Long Wavelength ◽  
Wavelength Emission

The paper presents on the synthesis and optical properties of mesomorphic composites, based on a glassy liquid-crystalline caprylate matrix, with  CdSе/ZnS hetero-nanoparticles. The synthesis of complex core-shell semiconductor nanoparticles was carried out by fusing together a cadmium caprylate composite with CdSе nanoparticles and zinc caprylate composite with ZnS nanoparticles. The cadmium and zinc chalcogenide nanoparticles have been synthesized in molten cadmium caprylate and zinc caprylate respectively. It has been found by optical spectroscopy that the have hetero-nanoparticles a core-shell structure. The effect of the composition (molar ratio of the components) of CdSе/ZnS hetero-nanoparticles on their spectral characteristics has been studied. It has been shown that the nanocomposites with hetero-nanoparticles are characterized by a more intense exciton fluorescence band than composites with individual CdSе or ZnS nanoparticles. It has been found that by varying the hetero-nanoparticle composition, one can change the core-shell thickness ratio and adjust thereby the absorption and emission band edge. As the number of ZnS nanoparticles in CdSе/ZnS hetero-nanoparticles increases some narrowing of the long- wavelength emission region first takes plase, which may be attributed to a reduction in the recombination of the smaller number of surface trapped exciton, and then, at a large ZnS content, a broadening of the long- wavelength emission region takes plase due to the extended CdSе/ZnS surface. It has been found that the main  contribution to the exciton fluorescence of nanocomposites with CdSе/ZnS hetero-nanoparticles is made by cadmium selenide nanoparticles, and that zinc sulfide nanoparticles enhance exciton fluorescence, also due to decrease in surface emission. It has been shown that the nanocomposites with hetero-nanoparticles are characterized by a more intense exciton fluorescence band that the nanocomposites with individual CdSе. The highest emission is observed in the case of the 35-55 % ZnS content of the shell, and at a smaller or larger amount of ZnS, emission intensity decreases.  

Eccentric 1-D magnetic core–shell photonic crystal balls: ingenious fabrication and distinctive optical properties

2018 ◽  
Vol 6 (16) ◽  
pp. 4531-4540 ◽  
Author(s):  
Huiru Ma ◽  
Yali Tan ◽  
Jie Cao ◽  
Sheron Chuanyu Lian ◽  
Ke Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Photonic Crystal ◽  
Magnetic Core ◽  
Band Gaps ◽  
Core Shell ◽  
Photonic Band Gaps ◽  
Structural Colors ◽  
Photonic Band ◽  
The Magnetic Field

Eccentric 1-D photonic crystal balls fabricated by light intensity-guided morphology-controllable polymerization demonstrate self-displaying structural colors and dynamically tunable bi-photonic band-gaps by the direction and intensity of the magnetic field.

Research on Preparation of Nano-Silver by Orthogonal Test

2011 ◽  
Vol 694 ◽  
pp. 142-145
Author(s):  
Bao Lin Tang ◽  
Guang Xue Chen ◽  
Qi Feng Chen ◽  
Jing Lei Tai
Keyword(s):  
Hydrazine Hydrate ◽  
Chemical Reduction ◽  
Orthogonal Test ◽  
Nano Particles ◽  
Molar Ratio ◽  
Surface Protection ◽  
Nano Silver ◽  
Potential Applications ◽  
Medical Electronic ◽  
Average Size

Nano-silver has received a great deal of attention in recent years for its various potential applications on medical, electronic, optical, etc. In this paper, we developed a simple way to synthesize nano-sized silver by liquid chemical reduction method with hydrazine hydrate as reductant and PVP as surface-protection reagent. In the experimental design, orthogonal test with three factors and three levels is adopted, which investigated the effect of instillation method, the PVP amount and the reaction temperature on the size and morphology of silver nano-particle. Through analyzing the orthogonal experimental results, the optimum conditions for nano-silver preparation is obtained, in which hydrazine hydrate solution is instilled into the mixture solution of silver nitrate and PVP, the molar ratio of PVP/AgNO3 is 1.5, and the temperature is 50°C. Scanning electron microscopy was used to characterize the morphology of silver nano-particles, and the results show that the dispersed spherical nano-particles with the average size of about 60 nm can be prepared in this work.

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