scholarly journals A Simple Approach to the Synthesis of Hexagonal-Shaped Silver Nanoplates

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
G. Cynthia Jemima Swarnavalli ◽  
V. Joseph ◽  
V. Kannappan ◽  
D. Roopsingh
Keyword(s):  
Simple Approach ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silver Nanoplates ◽  
Transmission Electron ◽  
Growth Method ◽  
Xrd Studies ◽  
20 Nm ◽  
Faceted Particles

This paper deals with the synthesis of hexagonal-shaped silver nanoplates with diameters ranging from 15 to 20 nm along with a smooth nanobulk of 120 nm. These nanoplates were prepared by a kinetically controlled solution growth method using mild reducing agent dextrose, polyvinylpyrrolidone (PVPMw40 kDa) as the capping agent and urea as a habit modifier and at a moderate temperature of50°C. The crystal structure of the highly faceted particles consists mostly of (111) surfaces as revealed by both X-ray diffraction (XRD) studies and transmission electron microscopy (TEM).

scholarly journals Enhanced Photocatalytic Activity of Vanadium-Doped SnO2 Nanoparticles in Rhodamine B Degradation

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
H. Letifi ◽  
Y. Litaiem ◽  
D. Dridi ◽  
S. Ammar ◽  
R. Chtourou
Keyword(s):  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Crystal Size ◽  
Sno2 Nanoparticles ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
Vanadium Concentration ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm

In this paper, we have reported a novel photocatalytic study of vanadium-doped SnO2 nanoparticles (SnO2: V NPs) in rhodamine B degradation. These NPs have been prepared with vanadium concentrations varying from 0% to 4% via the coprecipitation method. Structural, morphological, and optical properties of the prepared nanoparticles have been investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscope (TEM), and UV-Vis and photoluminescence (PL) spectroscopy. Structural properties showed that both undoped and SnO2: V NPs exhibited the tetragonal structure, and the average crystal size has been decreased from 20 nm to 10 nm with the increasing doping level of vanadium. Optical studies showed that the absorption edge of SnO2: V NPs showed a redshift with the increasing vanadium concentration. This redshift leads to the decrease in the optical band gap from 3.25 eV to 2.55 eV. A quenching in luminescence intensity has been observed in SnO2: V NPs, as compared to the undoped sample. Rhodamine B dye (RhB) has been used to study the photocatalytic degradation of all synthesized NPs. As compared to undoped SnO2 NPs, the photocatalytic activity of SnO2: V NPs has been improved. RhB dye was considerably degraded by 95% within 150 min over on the SnO2: V NPs.

scholarly journals Synthesis, Structure, and Luminescent Properties of Europium-Doped Hydroxyapatite Nanocrystalline Powders

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Florian Massuyeau ◽  
Liliana Violeta Constantin ◽  
Adrian Costescu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Textural Properties ◽  
Average Crystallite Size ◽  
Luminescent Properties ◽  
Nanocrystalline Powders ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Vibrational Studies ◽  
20 Nm

The luminescent europium-doped hydroxyapatite (Eu:HAp, Ca10−xEux(PO4)6(OH)2) with0≤x≤0.2nanocrystalline powders was synthesized by coprecipitation. The structural, morphological, and textural properties were well characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The vibrational studies were performed by Fourier transform infrared, Raman, and photoluminescence spectroscopies. The X-ray diffraction analysis revealed that hydroxyapatite is the unique crystalline constituent of all the samples, indicating that Eu has been successfully inserted into the HAp lattice. Eu doping inhibits HAp crystallization, leading to a decrease of the average crystallite size from around 20 nm in the undoped sample to around 7 nm in the sample with the highest Eu concentration. Furthermore, the samples show the characteristic5D0→7F0transition observed at 578 nm related to Eu3+ions distributed on Ca2+sites of the apatitic structure.

Nanoporous Ni and Ni-Cu Fabricated by Dealloying

2009 ◽  
Vol 1228 ◽  
Author(s):  
Masataka Hakamada ◽  
Yasumasa Chino ◽  
Mamoru Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Noble Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
20 Nm ◽  
Good Workability ◽  
Scanning Electron

AbstractMetallic nanoporous architecture can be spontaneously attained by dealloying of a binary alloy. The nanoporous architecture can be often fabricated in noble metals such as Au and Pt. In this study, nanoporous Ni, Ni-Cu are fabricated by dealloying rolled Ni-Mn and Cu-Ni-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al or Cu-Al intermetallic compounds, the initial alloys had good workability probably because of their fcc crystal structures. After the electrolysis of the alloys in (NH4)2SO4 aqueous solution, nanoporous architectures of Ni and Ni-Cu with pore and ligament sizes of 10–20 nm were confirmed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses suggested that Ni and Cu atoms form a homogeneous solid solution in the Ni-Cu nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between diffusivities of Ni and Cu at solid/electrolyte interface. Ni can reduce the pore and ligament sizes of resulting nanoporous architecture when added to initial Cu-Mn alloys.

SYNTHESIS AND PIXE CHARACTERIZATION OF CuInSe2 AND CuIn3Se5

2006 ◽  
Vol 16 (01n02) ◽  
pp. 127-136
Author(s):  
P. MALAR ◽  
TAPASH RANJAN RAUTRAY ◽  
V. VIJAYAN ◽  
S. KASIVISWANATHAN
Keyword(s):  
Electron Microscopy ◽  
Single Phase ◽  
Compositional Analysis ◽  
X Ray Diffraction ◽  
Stoichiometric Mixture ◽  
X Ray ◽  
Transmission Electron ◽  
Xrd Studies ◽  
Constituent Elements

Polycrystalline ingots of CuInSe 2 and CuIn 3 Se 5 were synthesized by melt-quench technique starting from the stoichiometric mixture of constituent elements. X-ray Diffraction (XRD) studies confirmed the single-phase nature of the materials. Compositional analysis by Particle Induced X-ray Emission (PIXE) showed that the compounds are near stoichiometric. Thin films of CuInSe 2 and CuIn 3 Se 5 were grown from pre-synthesized CuInSe 2 and CuIn 3 Se 5 powders. The films were polycrystalline, single-phase and near stoichiometric in nature, as indicated by Transmission Electron Microscopy (TEM) and PIXE studies.

An environmentally friendly method for the isolation of cellulose nano fibrils from banana rachis fibers

2016 ◽  
Vol 87 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vincent Mukwaya ◽  
Weidong Yu ◽  
Rabie AM Asad ◽  
Hajo Yagoub
Keyword(s):  
Electron Microscopy ◽  
Average Diameter ◽  
Enzyme Hydrolysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sonic Treatment ◽  
Xrd Studies ◽  
Environmentally Friendly Method ◽  
Derivative Thermogravimetry

Cellulose nano fibrils (CNFs) were isolated from banana rachis bran using enzyme hydrolysis with subsequent ultra-sonic treatment. The CNFs and bran were characterized by particle size distribution (only the CNFs), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy; the morphology of the banana rachis fiber and CNFs was observed using scanning electron microscopy and transmission electron microscopy, respectively. The furnished nano fibrils had an average diameter of 14.02 ± 2.10 nm and length of 619.6 ± 90.7 nm. The aspect ratio of the CNFs is in the range of long fibrils, that is 44.18. XRD studies revealed that CNFs (48.83%) were more crystalline than the banana bran (27.76%). TGA and derivative thermogravimetry thermograms showed that CNFs were more thermally stable than the bran.

Nanocrystallization of gas atomized Cu47Ti33Zr11Ni8Si1 metallic glass

2006 ◽  
Vol 21 (3) ◽  
pp. 597-607 ◽  
Author(s):  
S. Venkataraman ◽  
S. Scudino ◽  
J. Eckert ◽  
T. Gemming ◽  
C. Mickel ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Primary Crystallization ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
20 Nm ◽  
Annealing Experiments

Cu47Ti33Zr11Ni8Si1 metallic glass powder was prepared by gas atomization. Decomposition in the amorphous alloy and primary crystallization has been studied by differential scanning calorimetry (DSC), x-ray diffraction (XRD), and transmission electron microscopy (TEM). The glassy powder exhibits a broad DSC exotherm prior to bulk crystallization. Controlled annealing experiments reveal that this exotherm corresponds to a combination of structural relaxation and nanocrystallization. A uniform featureless amorphous contrast is observed in the TEM prior to the detection of nanocrystals of 4–6 nm in size. High-resolution TEM studies indicate that this nanocrystalline phase has a close crystallographic relationship with the γ–CuTi phase having a tetragonal structure. The product of the main crystallization event is also nanocrystalline, hexagonal Cu51Zr14, having dimensions of 20 nm. However, there is no evidence for possible amorphous phase separation prior to the nanocrystallization events.

A New Hydrothermal Route for Synthesis of Molybdenum Disulphide Nanorods and Related Nanostructures

2006 ◽  
Vol 6 (1) ◽  
pp. 168-174 ◽  
Author(s):  
Jyoti R. Ota ◽  
Suneel K. Srivastava
Keyword(s):  
Nitrogen Atmosphere ◽  
Simple Approach ◽  
Photoluminescence Spectra ◽  
Energy Dispersive Analysis ◽  
X Ray Diffraction ◽  
Molybdenum Disulphide ◽  
Hydrothermal Route ◽  
X Ray ◽  
20 Nm ◽  
Thermally Treated

A simple approach to prepare nanorods of Molybdenum Disulphide (MoS2) using hydrothermal method by reacting aqueous solutions of (NH4)6Mo7O24 · 4 H2O, C2H4NS and Na2S2O4 at 190 °C for 24 h is described. The hydrothermal product has been subsequently subjected to the thermal treatment in nitrogen atmosphere at 675 °C for 6 h and characterized. X-ray diffraction (XRD) of the hydrothermal product indicated the formation of MoS2 relatively with much lower crystallinity compared to when it thermally treated. Energy dispersive analysis (EDX) was done to know the chemical composition of the product. TEM showed onset growth of MoS2 nanorods within the hydrothermal products itself and in thermally treated products it was prominent with the diameter of the nanorods ranging between 10–20 nm. Photoluminescence spectra MoS2 nanorods shows an intense absorbance at around 429 nm. TGA of the MoS2 nanorods in air and nitrogen atmosphere has also been studied. The extent of formation of MoS2 from the precursors obtained at 190 °C for duration of 12, 18, and 24 h and annealed at 675 °C for 6 h under nitrogen atmosphere is also demonstrated based on XRD data.

Hydrothermally Grown Nanostructured Tungsten Trioxide (hydrate) Films and their Photocatalytic Properties

2012 ◽  
Vol 1406 ◽  
Author(s):  
Z. H. Jiao ◽  
X.W. Sun
Keyword(s):  
Tin Oxide ◽  
Tungsten Trioxide ◽  
Photoconversion Efficiency ◽  
Capping Agent ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photocatalytic Activities ◽  
Xrd Studies ◽  
Crystal Seed

ABSTRACTWe report the growth of sheet-like nanostructured tungsten trioxide hydrate (3WO3·H2O) film on fluorine doped tin oxide (FTO) substrate via a facile crystal-seed-assisted hydrothermal method by using CH3COONH4 as capping agent. Dense thin film composed of irregular blocks with smaller surface area was obtained without the addition of CH3COONH4. X-ray diffraction (XRD) studies indicated that both films were of orthorhombic structure. The nanosheet film grown with CH3COONH4 after dehydration showed highly improved photocatalytic activities than the nanoblock one. The maximum anodic photocurrents of 1.16 mA/cm2 for oxidization of methanol and 0.5 mA/cm2 for water splitting were obtained for the nanosheet film with a highest photoconversion efficiency of about 0.3% under simulated solar illumination.

scholarly journals Facile Synthesis of High {001} Facets Dominated BiOCl Nanosheets and Their Selective Dye-Sensitized Photocatalytic Activity Induced by Visible Light

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Da Zhang ◽  
Liang Chen ◽  
Chengjing Xiao ◽  
Jing Feng ◽  
Lingmin Liao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Atmospheric Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Sensitized ◽  
Selective Area ◽  
Transmission Electron ◽  
Organic Surfactant ◽  
20 Nm

Single-crystal BiOCl nanosheets, with high{001}facets exposed, were synthesized through a facile hydrolysis reaction under general atmospheric pressure, without adding any organic surfactant or agent. The thickness of the BiOCl nanosheets is about 20 nm, and the diameter is arranged from 200 to 400 nm. The structure of the BiOCl nanosheets was characterized by X-ray diffraction, energy disperse X-ray spectrum, transmission electron microscopy, and selective area electron diffraction. Moreover, three different dyes were used as model molecules to test the photocatalytic activity of BiOCl nanosheets under visible light. It was found that the BiOCl nanosheets possess selective photocatalytic behavior as their activity over RhB is much higher than that over MO or MB. Based on the analysis of the experimental results, the potential mechanism was discussed.

scholarly journals Cytotoxicity Property of Nano-TiO2Sol and Nano-TiO2Powder

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Pingting He ◽  
Jie Tao ◽  
Jianjun Xue ◽  
Yulan Chen
Keyword(s):  
Electron Microscope ◽  
Average Length ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Experimental Protocols ◽  
20 Nm

A homogeneous and transparent titania (TiO2) sol with nanosized anatase TiO2particles was prepared by hydrothermal synthesis method. The transmission electron microscope and X-ray diffraction were used to characterize the structure and morphology of particulates in the TiO2sol and purchased TiO2powder. The results show that the homogeneous anatase crystalline phase was formed and the size of the spindle-like particle in sol was about 20 nm in width and 150 nm in average length, and the particulates of the purchased powder were globular-like about 50 nm in diameter. In addition, a consistent set of in vitro experimental protocols was used to study the effects of nano-TiO2sol as prepared and nano-TiO2powder on mouse peritoneal macrophage. The cytotoxicity tests in vitro indicate that, with the increasing of TiO2sol concentration contaminated with the cells, the relative proliferation rate of macrophage cells was improved slightly after the cells contaminated for 24 h, but it reduced rapidly after contaminated for 48 h. The purchased nano-TiO2powder inhibited the growth of the cells obviously as cultivating with macrophage both for 24 h and 48 h.

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