Structural, Optical, and Photocatalytic Properties of ZnSe Nanoparticles Influenced by the Milling Time

ZnSe nanoparticles (NPs) were prepared by combining both hydrothermal and mechanical milling methods. Transmission electron microscopy images show that fabricated ZnSe NPs with a sphere-like shape have an average size (d) in the range of 20–100 nm, affected by changing the milling time from 10 to 60 min. All the samples crystalize in zincblende-type structure without impurities, as confirmed by analyzing X-ray diffraction patterns, Raman spectra, and energy-dispersive X-ray spectroscopy. Carefully checking Raman spectra, we have observed the broadening and redshift of vibration modes as decreasing NP size, which are ascribed to extra appearance of disorder and defects. The photoluminescence study has found a blue emission at 462 nm attributed to the excitonic near-band edge and a broad defect-related emission around 520–555 nm. Increasing milling time leads to the decrease in the exciton-emission intensity, while the defect-related emissions increase gradually. Interestingly, as decreasing d, we have observed an improved photodegradation of Rhodamine B under UV irradiation, proving application potentials of ZnSe NPs in photocatalytic activity.

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Homogeneity in the Polyether Alkoxide Sol‐Gel Synthesis of YBa2Cu3O7-δ

MRS Proceedings ◽

10.1557/proc-346-29 ◽

1994 ◽

Vol 346 ◽

Cited By ~ 1

Author(s):

Carol S. Houk ◽

Gary A. Burgoine ◽

Catherine J. Page

Keyword(s):

Sol Gel ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Diffraction Patterns ◽

Mapping Techniques ◽

Starting Solutions ◽

Average Size ◽

Sol Gel Synthesis ◽

Elemental Maps

ABSTRACTWe have investigated the homogeneity of sol‐gel derived YBa2Cu307‐s from the solution phase to the final product using transmission electron microscopy (TEM), x‐ray diffraction (XRD), and Energy Dispersive X‐ray (EDX) lateral mapping techniques. The starting solutions contain stoichiometric amounts of the metal 2‐(2‐methoxyethoxy)ethoxide components in 2‐(2‐methoxyethoxy)ethanol and appear to be homogeneous by TEM with a uniform distribution of particles having an average size of less than 40 â. Through elemental mapping we see elemental segregation in the high temperature (950 °C) products, which are orthorhombic by XRD. In elemental maps of gel samples fired to 700 °C, which are tetragonal by XRD, we also see elemental inhomogeneity within particles and phase zoning in maps of products from finely ground gels. A comparison of elemental maps and x‐ray diffraction patterns of the products from gel processing and conventional solid state processing is made.

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Thermal and Structural Characterization of Nanocomposite Iron Nitride - Alumina and Iron Nitride - Silica Particles

MRS Proceedings ◽

10.1557/proc-703-v9.16 ◽

2001 ◽

Vol 703 ◽

Author(s):

Ann M. Viano ◽

Sanjay R. Mishra

Keyword(s):

Particle Size ◽

Milling Time ◽

Iron Nitride ◽

X Ray Diffraction ◽

X Ray ◽

Thermal Peak ◽

Transmission Electron ◽

Diffraction Patterns ◽

The One

ABSTRACTNanocomposite iron nitride based powders are known to have enhanced magnetic and other physical properties. To further explore their potential for application in various fields, we have performed a systematic study of the iron nitride - alumina and iron nitride - silica systems. Iron nitride powder of composition FexN (2 < x < 4), containing both Fe3N and Fe4N phases, was mechanically milled with Al2O3 or SiO2 powder for 4, 8, 16, 32, and 64 hours at the following compositions; (FexN)0.2(Al2O3)0.8, (FexN)0.6(Al2O3)0.4, (FexN)0.2(SiO2)0.8, and (FexN)0.6(SiO2)0.4. Differential thermal analysis and X-ray diffraction were performed to investigate thermal and structural transitions as a function of milling time. As the milling time is increased, the thermal peak corresponding to Fe4N is diminished, while the one corresponding to Fe3N is enhanced. These transitions are correlated with X-ray diffraction patterns. All XRD peaks broaden as a function of milling time, corresponding to smaller particle size. Transmission electron microscopy also reveals a decrease in particle size as the milling time in increased.

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DSC-TGA Hydrogen Evaluation during Mechanical Milling of AlFe Intermetallic

Materials Science Forum ◽

10.4028/www.scientific.net/msf.755.105 ◽

2013 ◽

Vol 755 ◽

pp. 105-110 ◽

Cited By ~ 3

Author(s):

E. García de León M. ◽

O. Téllez-Vázquez ◽

C. Patiño-Carachure ◽

G. Rosas

Keyword(s):

Mechanical Milling ◽

Milling Time ◽

Hydrogen Generation ◽

Pure Aluminum ◽

High Energy ◽

Milling Process ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Diffraction Patterns

Fe40Al60 (at%) intermetallic alloy composition was obtained by conventional casting methods and subsequently subjected to high-energy mechanical milling under different conditions of humidity. All samples were characterized by X-ray diffraction patterns (XRD), transmission electron microcopy (TEM) and DSC-TGA thermogravimetric experiments. After the milling process, the amount of hydrogen generated was determined using thermogravimetric analysis and chemical reactions (stoichiometry). All techniques confirm the formation of bayerite phase which is attributed to the hydrogen embrittlement reaction between the intermetallic material and water to release hydrogen. It was observed that the hydrogen generation is increased as the ball milling time is increased. The quantity of hydrogen evaluated is similar to that obtained in previous reported experiments with pure aluminum and some of its alloys.

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Synthesis and Characterization of CoMn2O4 Nanopowders by a Reverse Micelle Processing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.868.105 ◽

2016 ◽

Vol 868 ◽

pp. 105-110

Author(s):

Dong Sik Bae

Keyword(s):

Reverse Micelle ◽

Molar Ratio ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

Xrd Diffraction ◽

Transmission Electron ◽

Diffraction Patterns ◽

Average Size

CoMn2O4 nanoparticles were synthesized by reverse micelle processing from the mixed precursor (consisting of Co (NO3)2 ·6H2O and MnCl2·4H2O). The CoMn2O4 was prepared by mixing the aqueous solution at a molar ratio of Co : Mn = 1 : 2. The synthesized powders were calcined at 600°C for 2h. The average size and distribution of synthesized powders were in the range of 10-20nm and narrow, respectively. The average size of the synthesized powders increased with increasing water to surfactant molar ratio. The XRD diffraction patterns show that the phase of CoMn2O4 was spinel (JCPDS no.77-0471). The synthesized and calcined powders were characterized by thermogravimetry-differential scanning calorimeter (TG-DSC), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The magnetic property of the powder was measured by Vibrating Sample Magneto-meter (VSM) at 298K. The effect of synthesis parameter, such as the molar ratio of water to surfactant, is discussed.

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Cetyltrimethylammonium bromide- and ethylene glycol-assisted preparation of mono-dispersed indium oxide nanoparticles using hydrothermal method

Chemical Papers ◽

10.2478/s11696-014-0543-9 ◽

2014 ◽

Vol 68 (8) ◽

Cited By ~ 5

Author(s):

Selvakumar Dhanasingh ◽

Dharmaraj Nallasamy ◽

Saravanan Padmanapan ◽

Vinod Padaki

Keyword(s):

Ethylene Glycol ◽

Hydrothermal Method ◽

Indium Oxide ◽

Cetyltrimethylammonium Bromide ◽

Oxide Nanoparticles ◽

X Ray Diffraction ◽

Hydrothermal Conditions ◽

X Ray ◽

Transmission Electron ◽

Diffraction Patterns

AbstractThe influence of cetyltrimethylammonium bromide and ethylene glycol on the size and dispersion of indium oxide nanoparticles prepared under hydrothermal conditions was investigated. The precursor compound, indium hydroxide, obtained by the hydrothermal method in the absence as well as the presence of cetyltrimethylammonium bromide, was converted to indium oxide by sintering at 400°C. The formation of nanoscale indium oxide upon sintering was ascertained by the characteristic infrared adsorption bands and X-ray diffraction patterns of indium oxide. Transmission electron microscopy and band gap values confirmed that the cetyltrimethylammonium bromide facilitated the formation of indium oxide nanoparticles smaller in size and narrower in distribution than those prepared without the assistance of cetyltrimethylammonium bromide.

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On the Mechanical Milling of the AlCuFe Icosahedral Phase with Water

Materials Science Forum ◽

10.4028/www.scientific.net/msf.793.23 ◽

2014 ◽

Vol 793 ◽

pp. 23-27

Author(s):

C. Patiño-Carachure ◽

J. Luis López-Miranda ◽

F. de la Rosa ◽

M. Abatal ◽

R. Pérez ◽

...

Keyword(s):

Electron Microscopy ◽

Milling Time ◽

Induction Furnace ◽

Icosahedral Phase ◽

Quasicrystalline Phase ◽

X Ray Diffraction ◽

Cast Sample ◽

X Ray ◽

Transmission Electron ◽

Icosahedral Quasicrystalline

In this investigation the Al64Cu24Fe12 alloy was melted in an induction furnace and solidified under normal casting conditions. The as-cast sample was subject to a heat treatment at 700 oC under argon atmosphere in order to obtain the icosahedral quasicrystalline phase in a monophase region. Subsequently, the icosahedral phase was milled for different times and water added conditions. The pre-alloyed and milled powders were characterized using scanning electron microscopy, X-Ray diffraction, and transmission electron microscopy. The experimental results showed that the icosahedral phase is sensitive to the reaction between water and aluminum of the quasicrystalline alloy to generate hydrogen. As the milling time and the amount of water are increased, the embrittlement reaction of the alloy is accentuated releasing more hydrogen.

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Facile Refluxing Synthesis of Hydroxyapatite Nanoparticles

Australian Journal of Chemistry ◽

10.1071/ch14642 ◽

2015 ◽

Vol 68 (8) ◽

pp. 1293 ◽

Cited By ~ 5

Author(s):

Pakvipar Chaopanich ◽

Punnama Siriphannon

Keyword(s):

Crystallite Size ◽

Reaction Times ◽

Single Step ◽

Hydroxyapatite Nanoparticles ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Aqueous Mixture ◽

Diffraction Patterns ◽

Microscopy Images

Hydroxyapatite (HAp) nanoparticles were successfully synthesized from an aqueous mixture of Ca(NO3)2·4H2O and (NH4)2HPO4 by a facile single-step refluxing method using polystyrene sulfonate (PSS) as a template. The effects of reaction times, pH, and PSS concentration on the HAp formation were investigated. It was found that the crystalline HAp was obtained under all conditions after refluxing the precursors for 3 and 6 h. The longer refluxing time, the greater the crystallinity and the larger the crystallite size of the HAp nanoparticles. The HAp with poor crystallinity was obtained at pH 8.5; however, the well-crystallized HAp was obtained when reaction pH was increased to 9.5 and 10.5. In addition, the X-ray diffraction patterns revealed that the presence of PSS template caused the reduction of HAp crystallite size along the (002) plane from 52.6 nm of non-template HAp to 43.4 nm and 41.4 nm of HAp with 0.05 and 0.2 wt-% PSS template, respectively. Transmission electron microscopy images of the synthesized HAp revealed the rod-shaped crystals of all samples. The synthesized HAp nanoparticles were modified by l-aspartic acid (Asp) and l-arginine (Arg), having negative and positive charges, respectively. It was found that the zeta potential of HAp was significantly changed from +5.46 to –24.70 mV after modification with Asp, whereas it was +4.72 mV in the Arg-modified HAp. These results suggested that the negatively charged amino acid was preferentially adsorbed onto the synthesized HAp surface.

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Formation of ZnO/Zn0.5Cd0.5Se Alloy Quantum Dots in the Presence of High Oleylamine Contents

Nanomaterials ◽

10.3390/nano9070999 ◽

2019 ◽

Vol 9 (7) ◽

pp. 999

Author(s):

Yi-An Chen ◽

Kuo-Hsien Chou ◽

Yi-Yang Kuo ◽

Cheng-Ye Wu ◽

Po-Wen Hsiao ◽

...

Keyword(s):

Electron Microscopy ◽

Quantum Dots ◽

Particle Size ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

Transmission Electron ◽

Average Size ◽

Alloy Quantum Dots ◽

First Time

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.

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A Chemical Solution Route to Rapid Synthesis of Homogeneous Bi100−xSbx Alloys Nanoparticles at Room Temperature

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2007.151 ◽

2007 ◽

Vol 7 (2) ◽

pp. 525-529 ◽

Cited By ~ 3

Author(s):

Bo Zhou ◽

Jun-Jie Zhu

Keyword(s):

Room Temperature ◽

Raw Materials ◽

X Ray Diffraction ◽

X Ray ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Solution Route ◽

Diffraction Patterns ◽

Co Reduction ◽

Chemical Solution Route

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.

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Synthesis and Characterization of Cu2FeSnS4 Semiconductor Nanocrystals with Zincblende Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.2019 ◽

2012 ◽

Vol 512-515 ◽

pp. 2019-2022 ◽

Cited By ~ 1

Author(s):

Xiao Lu Liang ◽

Xian Hua Wei

Keyword(s):

Random Distribution ◽

Semiconductor Nanocrystals ◽

Synthesis And Characterization ◽

X Ray Diffraction ◽

X Ray ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Nir Absorption ◽

Average Size

Cu2FeSnS4semiconductor nanocrystals with zincblende structure have been successfully synthesized by a hot-injection approach. Cu+, Fe2+, and Sn4+cations have a random distribution in the zincblende unit cell, and the occupancy possibilities are 1/2, 1/4 and 1/4, respectively. Those nanocrystals were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectroscopy (EDS), and UV-Vis-NIR absorption spectroscopy. The Cu2FeSnS4 nanocrystals have an average size of 7.5 nm and a band gap of 0.92 eV.

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