scholarly journals Synthesis and Study of CdSe QDs by a Microfluidic Method and via a Bulk Reaction

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 368 ◽  
Author(s):  
Jinfeng Liu ◽  
Yarong Gu ◽  
Qirui Wu ◽  
Xiaohong Wang ◽  
Lijuan Zhao ◽  
...  
Keyword(s):  
Growth Process ◽  
Crystal Growth Rate ◽  
Cdse Quantum Dots ◽  
Residence Times ◽  
Cdse Qds ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Bulk Reaction ◽  
Visible Absorption Spectroscopy

In this work, we synthesized monodispersed CdSe quantum dots (QDs) by a microfluidic method and via a bulk reaction. The structures of the CdSe QDs were characterized by X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). The optical properties of the prepared CdSe QDs were determined using ultraviolet-visible absorption spectroscopy and photoluminescence spectroscopy. The CdSe QDs obtained by the microfluidic method have a faster crystal growth rate and a higher absolute photoluminescence quantum yield than those obtained via the bulk reaction. Additionally, we investigated the growth process of the CdSe QDs with increasing residence times.

Synthesis and Characterizations of Nanocubes, Monodispersed Nanocrystals and Nanospheres of Au

2007 ◽  
Vol 353-358 ◽  
pp. 2163-2166
Author(s):  
Ming Yang ◽  
Guo Qing Zhou ◽  
Jiang Guo Zhao ◽  
Zhan Jun Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Powder Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Scherrer Formula ◽  
Visible Absorption Spectroscopy

Nanocubes, monodispersed nanocrystals and nanospheres of Au have been prepared by a simple reaction between HAuCl4·4H2O, NaOH and NH2OH·HCl in the presence of gelatin. The role of gelatin and the affection of pH in producing the nanoparticles of Au were discussed. The products were characterized by X-ray powder diffraction, transmission electron microscopy, and UV-visible absorption spectroscopy. The sizes of the monodispersed nanocrystals of Au were estimated by Debye-Scherrer formula according to XRD spectrum.

The Hydrothermal Synthesis of ZrO2 Nanoparticles and their Optical Absorption Properties

2013 ◽  
Vol 873 ◽  
pp. 164-167
Author(s):  
Xiao Ming Fu
Keyword(s):  
Optical Absorption ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Ammonia Water ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Absorption Spectroscopy

ZrO2 nanoparticles with a diameter range of less than 10 nm are successfully synthesized with zirconium nitrate as zirconium source and stronger ammonia water as precipitant at 210 °C for 48 h via the easy hydrothermal method. The phase, the morphologies and optical absorption properties of the samples have been characterized and analyzed by X-ray diffraction (XRD), field-emission transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS), respectively. XRD analysis shows that the phase of as obtained samples is ZrO2. TEM analysis confirms that using stronger ammonia water as precipitant instead of NaOH and the increase of the reaction temperature are in favor of the synthesis of ZrO2 nanoparticles. And UV-VIS measurements show that ZrO2 nanoparticles have a good optical absorption property.

Synthesis and photocatalytic hydrogen evolution of meso-tetrakis(p-sulfonatophenyl)porphyrin functionalized platinum nanocomposites

2010 ◽  
Vol 14 (06) ◽  
pp. 540-546 ◽  
Author(s):  
Lingling Zhang ◽  
Yongtao Lu ◽  
Yukou Du ◽  
Ping Yang ◽  
Xiaomei Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Antenna System ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Absorption Spectroscopy

Meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS4) functionalized platinum nanocomposites were synthesized and characterized using ultraviolet-visible absorption spectroscopy (UV-vis), fluorescence spectroscopy (FL), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD) methods. The postulated configuration of TPPS4 functionalized platinum nanocomposite may be described as an antenna system containing a photoreceptive TPPS4 shell and a nanosize platinum core. Fluorescence and photoelectrochemistry studies of both TPPS4 and the platinum nanocomposites showed that efficient electron/energy transfer occurred from the TPPS4 donor to the metallic nanocore acceptor. TPPS4 functionalized platinum nanocomposites are photocatalytic active for water reduction to produce hydrogen. The turnover numbers (TONPt and TONTPPS4) and quantum yield of hydrogen (ϕH2) for the photocatalyst (nPt:nTPPS4= 250) were 44, 11056, and 1.8%, respectively, calculated on the basis of the total amount of H2 evolution for 12 h irradiation.

scholarly journals Synthesis and Characterization of Nanorods in Sucrose Ester Water-in-Oil Microemulsion

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
N. M. Huang
Keyword(s):  
Reaction Time ◽  
Sucrose Ester ◽  
Synthesis And Characterization ◽  
Microemulsion System ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Visible Absorption Spectroscopy

We report the synthesis of nanorods in a nonionic sugar-based water-in-oil (w/o) microemulsion system using food grade sucrose ester as biosurfactant. was formed by mixing indium (III) chloride and thioacetamide in the water core of the microemulsion system. The as-prepared yellowish was characterized by X-ray diffractometry (XRD), UV-visible absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Formation of spherical or rod-like nanomaterials was dependent on reaction time. Rod-like , arranged in bundles, was formed only after 2 days of reaction time. Upon longer aging time, a mixture of rod-like and spherical was formed. A plausible formation mechanism of the nanorods in the sucrose ester microemulsion was postulated. The diameter of the nanorods was found to be very small, which is  nm with aspect ratio of 20 : 1 (length : diameter).

The Influence of the Hydrothermal Temperature on the Morphologies and the Optical Absorption Properties of M-ZrO2 Nanoparticles

2013 ◽  
Vol 320 ◽  
pp. 11-14
Author(s):  
Xiao Ming Fu
Keyword(s):  
Optical Absorption ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Absorption Spectroscopy

M-ZrO2 nanoparticles with a diameter range of about 10 nm are successfully synthesized with zirconium nitrate as zirconium source and stronger ammonia water as precipitant at 210 °C for 48 h via the easy hydrothermal method. The phase, the morphologies and optical absorption properties of the samples have been characterized and analyzed by X-ray diffraction (XRD), field-emission transmission electron microscopy (TEM) and ultraviolet-visible absorption spectroscopy (UV-VIS), respectively. XRD analysis shows that the phase of as obtained samples is M-ZrO2. TEM analysis confirms that the increase of the reaction temperature is in favor of the synthesis of M-ZrO2 nanoparticles. And UV-VIS measurements show that M-ZrO2 nanoparticles have a good optical absorption property.

Synthesis and Characterizations of Monodispersed Nanotriangle of Gold

2012 ◽  
Vol 455-456 ◽  
pp. 549-552
Author(s):  
Kai Cheng Zhang ◽  
Si Ying Zhao
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Decisive Role ◽  
Direct Reaction ◽  
Visible Absorption ◽  
Gold Particles ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Visible Absorption Spectroscopy

Monodispersed nanotriangles of gold have been prepared by a simple reaction between HAuCl4·4H2O, KOH and NH2OH·HCl in the presence of gelatin. Gelatin played a decisive role as an inhibitor of the direct reaction of NH2OH with AuCl4- and coagulation of the growing gold in producing the triangle. In the absence of gelatin, we can only obtain irregular large gold particles. The products were characterized by X-ray powder diffraction, transmission electron microscopy and UV-visible absorption spectroscopy.

Synthesis and Characterisation of Bicone-Shaped and Monodispersed Nanoparticles of Cu2S

2011 ◽  
Vol 194-196 ◽  
pp. 755-758
Author(s):  
Ming Yang ◽  
Kui Zhou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Powder Diffraction ◽  
Band Gaps ◽  
Optical Measurements ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
Visible Absorption Spectroscopy

Bicone-shaped and monodispersed nanoparticles of Cu2S have been prepared by a simple reaction between CuO suspension, NH2OH•HCl and (NH4)2S in the presence of gelatin at 5°C. The products were characterized by X-ray powder diffraction, transmission electron microscopy and UV-visible absorption spectroscopy. The band gaps are estimated to be 1.98 eV and 2.03 eV according to the results of optical measurements of bicone-shaped and monodispersed nanoparticles of Cu2S.

CdSe/ZnS core–shell QDs: Synthesis and investigating optical properties

2016 ◽  
Vol 30 (08) ◽  
pp. 1650093 ◽  
Author(s):  
M. Molaei ◽  
F. Sarhani ◽  
F. Salari Bardsiri ◽  
M. Karmipour
Keyword(s):  
Room Temperature ◽  
Thioglycolic Acid ◽  
Cdse Quantum Dots ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Cdse Qds ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible

In this work, CdSe quantum dots (QDs) were synthesized using a microwave activated reaction between NaHSe and CdSO4 in the presence of thioglycolic acid (TGA) as capping molecule and then using a one-pot method, ZnS shell was grown subsequently around CdSe cores by a room temperature reaction based on the photo-sensitivity of Na2S2O3 dissociation. Synthesized QDs were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV-visible (UV-Vis) and photoluminescence (PL) spectroscopy. All these analyses confirmed the formation of CdSe QDs and successful growth of ZnS shell around CdSe cores.

Photoluminescence Enhancement of CdS Nanocrystals Fabricated on Dithiocarbamate Functionalized PET Substrates

2012 ◽  
Vol 512-515 ◽  
pp. 1511-1515
Author(s):  
Chun Lin Zhao ◽  
Li Xing ◽  
Xiao Hong Liang ◽  
Jun Hui Xiang ◽  
Fu Shi Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hexagonal Structure ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Morphological Studies ◽  
Transmission Electron

Cadmium sulfide (CdS) nanocrystals (NCs) were self-assembled and in-situ immobilized on the dithiocarbamate (DTCs)-functionalized polyethylene glycol terephthalate (PET) substrates between the organic (carbon disulfide diffused in n-hexane) –aqueous (ethylenediamine and Cd2+ dissolved in water) interface at room temperature. Powder X-ray diffraction measurement revealed the hexagonal structure of CdS nanocrystals. Morphological studies performed by scanning electron microscopy (SEM) and high-resolution transmission electron microscope (HRTEM) showed the island-like structure of CdS nanocrystals on PET substrates, as well as energy-dispersive X-ray spectroscopy (EDS) confirmed the stoichiometries of CdS nanocrystals. The optical properties of DTCs modified CdS nanocrystals were thoroughly investigated by ultraviolet-visible absorption spectroscopy (UV-vis) and fluorescence spectroscopy. The as-prepared DTCs present intrinsic hydrophobicity and strong affinity for CdS nanocrystals.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

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