scholarly journals Rapid microwave-assisted synthesis of molybdenum trioxide nanoparticles

2019 ◽  
Vol 16 (3) ◽  
pp. 33
Author(s):  
Nguyen Thi Minh Nguyet ◽  
Vuong Vinh Dat ◽  
Nguyen Anh Tien ◽  
Le Van Thang Thang
Keyword(s):  
Electron Microscopy ◽  
Molybdenum Trioxide ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
Ammonium Heptamolybdate ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Heat Treated ◽  
Short Period

In this paper, molybdenum trioxide (MoO3) nanoparticles were synthesized by rapid-microwave method using ammonium heptamolybdate (AHM) as a precursor in ethylene glycol (EG) solution with concentrated HNO3. This reaction was carried out in a short period of 30 min and the nanoparticles were then heat treated at 600°C. The structures ofthe products were  analyzed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to record the morphology and nanoparticle size of MoO3. The Raman spectrum of MoO3 displays three well-defined peaks located at 989.2, 816.0 and 665.3 cm-1 which are the fingerprints of the orthorhombicα-MoO3 crystalline phase.

scholarly journals Microwave-assisted synthesis, characterization and photoluminescence of shuttle-like BaMoO4 microstructure

2015 ◽  
Vol 33 (3) ◽  
pp. 537-540 ◽  
Author(s):  
Anukorn Phuruangrat ◽  
Budsabong Kuntalue ◽  
Titipun Thongtem ◽  
Somchai Thongtem
Keyword(s):  
Electron Microscopy ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

Abstract Shuttle-like BaMoO4 microstructure has been successfully synthesized from Ba(N03)2·4H20 and Na2MoO4·2H2O as starting materials in ethylene glycol solvent containing 20 mL 5 M NaOH by microwave radiation at 180 W for 30 min. The as- synthesized BaMoO4 product was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photolumines­cence (PL) spectroscopy. XRD patterns revealed that the products was tetragonal BaMoO4 phase. SEM and TEM characteriza­tion showed that the product had a shuttle-like BaMoO4 microstructure. PL of the shuttle-like BaMoO4 microstructure showed a maximum emission at 466 nm excited by 280 nm wavelength.

Copper(I) Halide Nanoparticle-dispersed Glasses Prepared by Copper Staining

2005 ◽  
Vol 20 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Kohei Kadono ◽  
Tatsuya Suetsugu ◽  
Takeshi Ohtani ◽  
Toshihiko Einishi ◽  
Takashi Tarumi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Surface Region ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Heat Treated ◽  
Glass Heat

Copper(I) chloride and bromide nanoparticle-dispersed glasses were prepared by means of a conventional copper staining. The staining was performed by the following process: copper stain was applied on the surfaces of Cl−- or Br−-ion-containing borosilicate glasses, and the glasses were heat-treated at 510 °C for various times. Typical exciton bands observed in the absorption spectra of the glasses after the heat treatment indicated that CuCl and CuBr particles were formed in the surface region of the glasses. The average sizes of the CuCl and CuBr particles in the glasses heat-treated for 48 h were estimated at 4.8 and 2.7 nm, respectively. The nanoparticles were also characterized by x-ray diffraction and transmission electron microscopy. Depth profiles of Cu and CuBr concentration in the glass heat-treated for 48 h were measured. Copper decreased in concentration monotonously with depth, reaching up to 60 μm, while the CuBr concentration had a maximum at about 25 μm in depth.

Double Periodicity Formation in EuTe/PbTe Superlattices

1995 ◽  
Vol 399 ◽  
Author(s):  
M. Shima ◽  
L. Salamanca-Riba ◽  
G. Springholz ◽  
G. Bauer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Short Period ◽  
Short Period Superlattices

ABSTRACTMolecular beam epitaxy was used to grow EuTe(x)/PbTe(y) short period superlattices with x=1-4 EuTe(111) monolayers alternating with y≈3x PbTe monolayers. The superlattices were characterized by transmission electron microscopy and high resolution x-ray diffraction. Regions with double periodicity were observed coexisting with areas of nominal periodicity. The sample with x=3.5 and y=9, for example, contains regions with double periodicity of x=7 and y=17. X-ray diffraction measurements confirm the formation of the double periodicity in these samples by the appearance of weak satellites in between the satellites of the nominal periodicity. The double periodicity in the superlattice is believed to result from interdiffusion during the growth. A model for this process is presented.

Rapid Synthesis of Uniform CdSe Nanorods by a Microwave-Assisted Solvothermal Method in Ethylenediamine

2020 ◽  
Vol 20 (10) ◽  
pp. 6495-6499
Author(s):  
Maokun Han ◽  
Ruijuan Qi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solvothermal Method ◽  
X Ray Diffraction ◽  
Rapid Synthesis ◽  
X Ray ◽  
Microwave Assisted ◽  
Aspect Ratios ◽  
Transmission Electron ◽  
Cdse Nanorods

A rapid microwave-assisted solvothermal method is reported for the synthesis of uniform CdSe nanorods in ethylenediamine (EDA) using CdCl2 and elemental Se as reactants. The resultant nanorods have a diameter of approximately 10 nm and a length of approximately 300 nm. Our experiments show that the concentrations of EDA and CdCl2 play important roles in product morphology. The well-dispersed CdSe nanorods with high aspect ratios were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), UV-vis absorption and photoluminescence (PL).

Heat Treatment of Nanocrystalline Al2O3-Zr02

1996 ◽  
Vol 457 ◽  
Author(s):  
Bridget M. Smyser ◽  
Jane F. Connelly ◽  
Richard D. Sisson ◽  
Virgil Provenzano
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Grain Size ◽  
Monoclinic Phase ◽  
Phase Distribution ◽  
Critical Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated

ABSTRACTThe effects of grain size on the phase transformations in nanocrystalline ZrO2-Al2O3 have been experimentally investigated. Compositions from 10 to 50 vol% Al2O3 in ZrO2 were obtained as a hydroxide gel. The powders were then calcined at 600 °C for 17 hours and heat treated at 1100 °C for 24 and 120 hours and at 1200 °C for 2 hours. The phase distribution and grain size were determined using x-ray diffraction and transmission electron microscopy. The initial grain size after calcining was 8–17 nm. It was determined that the critical ZrO2 grain size to avoid the tetragonal to monoclinic phase transformation on cooling from 1100 °C was between 17 and 25 nm. Samples containing 50% Al2O3 maintained a grain size below the critical size for all times and temperatures. The 30% Al2O3 samples showed the same behavior in all but one heat treatment. The remainder of the samples showed significant grain growth and at least partial transformation to the monoclinic phase.

Microwave-Assisted Hydrothermal Preparation of SnO2/MoS2 Composites and their Electrochemical Performance

NANO ◽  
2016 ◽  
Vol 11 (02) ◽  
pp. 1650023 ◽  
Author(s):  
Lin Ma ◽  
Xiaoping Zhou ◽  
Limei Xu ◽  
Xuyao Xu ◽  
Lingling Zhang
Keyword(s):  
Electron Microscopy ◽  
Synergetic Effect ◽  
Electrochemical Performances ◽  
Microwave Method ◽  
X Ray Diffraction ◽  
Hydrothermal Preparation ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Mean Size

We introduce a two-step hydrothermal and microwave method to prepare novel SnO2/MoS2 composites. The as-prepared samples are well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The experimental results indicate that the SnO2/MoS2 composites are composed of MoS2 nanosheets and ultrafine SnO2 nanoparticles with mean size of 3–4[Formula: see text]nm which are well-distributed and anchored on the surface of MoS2 nanosheets. The resultant composites demonstrate prominently improved electrochemical performances, which could be attributed to the unique and robust microstructures and synergetic effect between MoS2 and SnO2.

Structures and phase transitions of B-Ta2O5 and Z-Ta2O5: two high-pressure forms of Ta2O5

2000 ◽  
Vol 56 (4) ◽  
pp. 659-665 ◽  
Author(s):  
I. P. Zibrov ◽  
V. P. Filonenko ◽  
M. Sundberg ◽  
P.-E. Werner
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Pressure ◽  
Rietveld Method ◽  
High Pressure Chamber ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated

A sample of Ta2O5, ditantalum pentaoxide, heat-treated in a `toroid'-type high-pressure chamber at P = 8 GPa and T = 1470 K, was studied by X-ray powder diffraction and high-resolution transmission electron microscopy (HRTEM). Two high-pressure modifications of Ta2O5, isostructural with B-Nb2O5 and Z-Nb2O5, were identified from the X-ray powder pattern. Both structures were refined by the Rietveld method from the X-ray diffraction data: B-Ta2O5, a = 12.7853 (4), b = 4.8537 (1), c = 5.5276 (2) Å, β = 104.264 (2)°, V = 332.45 Å3, Z = 4, space group C2/c; Z-Ta2O5, a = 5.2252 (1), b = 4.6991 (1), c = 5.8534 (1) Å, β = 108.200 (2)°, V = 136.53 Å3, Z = 2, space group C2. The Z-Ta2O5 modification is new. The Ta atoms are six-coordinated in B-Ta2O5 and seven-coordinated in Z-Ta2O5. The two structures are closely related, which makes an intergrowth and a transformation between them possible. An idealized model of the intergrowth structure has been given. The HRTEM study showed defect-rich B-Ta2O5 crystals, which could be interpreted as an intergrowth between the B-Ta2O5 and Z-Ta2O5 phases.

Synthesis of Nano Onion-Like Fullerenes Using Iron Supported on Sodium Chloride as Catalyst by Decomposing Acetylene

2011 ◽  
Vol 393-395 ◽  
pp. 370-372
Author(s):  
Cun Jing Wang ◽  
Peng Yao ◽  
Gai Rong Chen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sodium Chloride ◽  
Catalytic Decomposition ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Scanning Electron

Catalytic decomposition of acetylene was carried out at 400 °C using iron supported on sodium chloride as catalyst and the product was heat-treated at 650 °C under an argon atmosphere for 2 h directly. The sample was examined by scanning electron microscopy, high resolution transmission electron microscopy and X-ray diffraction. The results show that nano onion-like fullerenes encapsulating Fe cores with diameters in the range 20-50 nm were obtained.

scholarly journals Relationship between Crystal Shape, Photoluminescence, and Local Structure inSrTiO3Synthesized by Microwave-Assisted Hydrothermal Method

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Luís F. da Silva ◽  
Waldir Avansi ◽  
Mário L. Moreira ◽  
Alexandre Mesquita ◽  
Lauro J. Q. Maia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Spherical Particles ◽  
Lower Amount ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
X Ray Absorption

This paper describes the effect of using different titanium precursors on the synthesis and physical properties of SrTiO3powders obtained by microwave-assisted hydrothermal method. X-ray diffraction measurements, X-ray absorption near-edge structure (XANES) spectroscopy, field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HRTEM) were carried out to investigate the structural and optical properties of the SrTiO3spherical and cubelike-shaped particles. The appropriate choice of the titanium precursor allowed the control of morphological and photoluminescence (PL) properties of SrTiO3compound. The PL emission was more intense in SrTiO3samples composed of spherelike particles. This behavior was attributed to the existence of a lower amount of defects due to the uniformity of the spherical particles.

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