Reactive Gas Condensation Synthesis of Aluminum Nitride Nanoparticles

2006 ◽  
Vol 6 (1) ◽  
pp. 146-150 ◽  
Author(s):  
Colin C. Baker ◽  
Abdullah Ceylan ◽  
S. Ismat Shah
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Photoelectron Spectroscopy ◽  
Temporal Stability ◽  
Gas Mixture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Condensation ◽  
Diffraction Patterns ◽  
Reactive Gas

Aluminum Nitride (AlN) nanoparticles were synthesized using a Reactive Gas Condensation (RGC) technique in which a mixture of ammonia (NH3) and nitrogen (N2) gases were used for the nitridation of aluminum. NH3 served as the reactive gas, while N2 served as both a carrier gas and the inert source for particle condensation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses revealed that at reactive gas compositions greater than 10% NH3 in N2, samples were composed entirely of hexagonal AlN nanoparticles. Electron diffraction patterns showed single crystal hexagonal AlN structure. The particle size was controlled by varying the pressure of the gas mixture. AlN nanoparticles were dispersed in a liquid matrix to enhance thermal conductivity. Results showed that a minimal addition of AlN increased the thermal conductivity of hydrocarbon pump oil by approximately 27%. The thermal conductivity became constant after reaching a maximum above 0.01 wt% AlN. Temporal stability of AlN was studied by XRD. Samples exposed to air for extended periods of time and analyzed by XRD show no degradation of crystalline AlN nanoparticles.

Surface Characterization of Carbon-Bearing Magnetite (CBM) and Carbon-Bearing Ni(II)-Ferrite (CBNF)

1994 ◽  
Vol 344 ◽  
Author(s):  
T. Sano ◽  
K. Akanuma ◽  
M. Tsuji ◽  
Y. Tamaura
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spinel Structure ◽  
Surface Characterization ◽  
Carbon Deposition ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Oxygen Ions ◽  
Diffraction Patterns

AbstractOxygen-deficient magnetite (ODM; Fe3O4-δ, δ>0) synthesized by reduction of magnetite with H2 at 300°C decomposed CO2 to carbon with an efficiency of nearly 100% at 300°C. In this reaction, two oxygen ions of the CO2 were incorporated into the spinel structure of ODM and carbon was deposited on the surface of ODM with zero valence to form visible particles. The particles of carbon separated from ODM were studied by Raman, energy-dispersive X-ray and wave-dispersive X-ray spectroscopies. The carbon which had been deposited on the ODM was found to be a mixture of graphite and amorphous carbon in at least two levels of crystallization. X-ray photoelectron spectroscopy and X-ray diffraction patterns of the carbon-bearing magnetite (CBM) showed no indication of carbide (Fe3C) or metallic iron (α-Fe) phase formation. In the C 1s XPS spectra of the CBM, no peaks were observed which could be assigned to CO2 or CO. X-ray diffractometry, chemical analysis and TG-MS measurement showed that the carbon-bearing Ni(II)-ferrite (CBNF) (Ni(II)/Fetotal = 0.15) synthesized by the carbon deposition reaction from CO2 with the H2-reduced Ni(II)-ferrite was represented by (Ni0.28Fe2.72O4.00)1-δ (Ni2+06.9Fe2+2.31O3.00)δCτ (δ= 0.27, τ= 0.17). The carbon of the CBNF gave the CIOlayer-like oxide containing some Ni2+ ions.

Effect of zirconium addition on the phase evolution of chromium zirconium nitride prepared by magnetron sputtering

2020 ◽  
Vol 62 (8) ◽  
pp. 783-787
Author(s):  
Patama Visuttipitukul ◽  
Kumpon Leelaruedee ◽  
Hideyuki Kuwahara ◽  
Atchara Khamkongkaeo ◽  
Niti Yongvanich ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Phase Evolution ◽  
Zirconium Nitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Residual Oxygen ◽  
Crystallite Sizes ◽  
Nanoscale Structure ◽  
Reactive Gas

Abstract In the research reported in this contribution, chromium-zirconium nitride (CrZrN) layers were deposited on (100) silicon wafer by balance magnetron sputtering using argon and nitrogen as working and reactive gas, respectively. The coating layers were categorized into three groups according to zirconium content; low-zirconium (Low-Zr), medium-zirconium (Med-Zr) and high-zirconium (High-Zr). All layers had thicknesses in the range of 1.0-1.3 μm and the Med-Zr was the thickest sample. From the X-ray diffraction (XRD) results, zirconium could partially dissolve in chromium nitride (CrN) and formed complex nitride of chromium-zirconium [(Cr,Zr)N]. This phasic group was dominant for all samples, and the average crystallite sizes decreased with increasing zirconium fraction. In addition, the High-Zr sample had an extra broadened peak among (Cr,Zr)N peaks which could not clearly be identified by XRD. This ambiguity was eliminated by X-ray photoelectron spectroscopy (XPS). It was determined to be amorphous of zirconium oxynitride (Zr2ON2). Because of the high oxygen sensitivity of zirconium, it reacted with nitrogen and residual oxygen forming Zr2ON2. This study is among the first to examine the resulting nanoscale structure of the CrN layers incorporated with a high amount of zirconium.

scholarly journals Ag/AgCl/MIL-101(Fe) Catalyzed Degradation of Methylene Blue under Visible Light Irradation

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1453 ◽  
Author(s):  
Yun Liu ◽  
Yuanhong Xie ◽  
Mingjin Dai ◽  
Qingjiao Gong ◽  
Zhi Dang
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Box Behnken Design ◽  
X Ray ◽  
Plasmonic Material ◽  
Fenton Catalyst ◽  
Diffraction Patterns

A novel photo-Fenton catalyst named Ag/AgCl/MIL-101(Fe) was synthesized by the method of precipitation and photo reduction and characterized by X-ray diffraction patterns (XRD), Brunauer-Emmett-Teller (BET) measurements, Fourier transform infrared spectra (FTIR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra. Moreover, the catalytic activity of the synthesized catalyst was tested using methylene blue (MB) as the target pollutant. The obtained results illustrated that the plasmonic material Ag/AgCl was successfully loaded on MIL-101(Fe) and the obtained catalyst exhibited an excellent catalytic activity under visible light at the neutral pH. According to the analyses of Plackett-Burman and Box-Behnken design, the optimum conditions for MB degradation were obtained. Under these conditions, the MB decolorization and mineralization efficiencies could reach to 99.75% and 65.43%, respectively. The recycling experiments also showed that the as-prepared catalyst displayed good reusability. In addition, the possible reaction mechanisms for the heterogeneous photo-Fenton system catalyzed by Ag/AgCl/MIL-101(Fe) were derived. The synthesized catalyst provides a promising approach to degrade organic pollutants in waste water.

scholarly journals Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

2019 ◽  
Vol 10 ◽  
pp. 9-21 ◽  
Author(s):  
Florian Dumitrache ◽  
Iuliana P Morjan ◽  
Elena Dutu ◽  
Ion Morjan ◽  
Claudiu Teodor Fleaca ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Laser Energy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Pyrolysis ◽  
One Step ◽  
Diffraction Patterns ◽  
Tin Oxide Nanoparticles ◽  
Co Doped

Zn/F co-doped SnO2 nanoparticles with a mean diameter of less than 15 nm and a narrow size distribution were synthesized by a one-step laser pyrolysis technique using a reactive mixture containing tetramethyltin (SnMe4) and diethylzinc (ZnEt2) vapors, diluted Ar, O2 and SF6. Their structural, morphological, optical and electrical properties are reported in this work. The X-ray diffraction (XRD) analysis shows that the nanoparticles possess a tetragonal SnO2 crystalline structure. The main diffraction patterns of stannous fluoride (SnF2) were also identified and a reduction in intensity with increasing Zn percentage was evidenced. For the elemental composition estimation, energy dispersion X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) measurements were performed. In general, both analyses showed that the Zn percentage increases with increasing ZnEt2 flow, accompanied at the same time by a decrease in the amount of F in the nanopowders when the same SF6 flow was employed. The Raman spectra of the nanoparticles show the influence of both Zn and F content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn dopant concentration).

scholarly journals A multi-method characterization of natural terrestrial birnessites

2020 ◽  
Vol 105 (6) ◽  
pp. 833-847
Author(s):  
Florence T. Ling ◽  
Jeffrey E. Post ◽  
Peter J. Heaney ◽  
Cara M. Santelli ◽  
Eugene S. Ilton ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Large Set ◽  
X Ray Diffraction ◽  
Full Spectrum ◽  
X Ray ◽  
High Concentrations ◽  
Diffraction Patterns ◽  
X Ray Absorption ◽  
Crystal Structure And Chemistry

Abstract With a focus on a large set of natural birnessites collected from terrestrial, freshwater systems, we applied and compared the capabilities of X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) to characterize crystal structure and chemistry. Using XRD, we successfully identified 3 of the 11 natural birnessite samples as hexagonal ranciéite-like phases, but the remaining samples yielded less interpretable “3-line” diffraction patterns with broad, asymmetrical peaks at d-spacings of ~7.2, ~2.4, and ~1.4 Å. EXAFS analysis suggested that many of these samples had characteristics of both triclinic and hexagonal birnessite. However, application of EXAFS to the ranciéite-like phases yielded unreasonably high concentrations of triclinic birnessite as an intergrowth, calling into question the use of synthetic hexagonal H-birnessite as an appropriate standard in the linear combination fitting of EXAFS data for natural birnessites. FTIR spectroscopy of the “3-line” birnessite samples successfully distinguished triclinic and hexagonal constituents, and analyses of peak positions suggested that natural birnessites occur as a full spectrum of triclinic and hexagonal intergrowths. XPS analysis of these samples revealed that higher Mn3+ concentrations relative to Mn2+ and Mn4+ are correlated to increased proportions of triclinic birnessite.

CO2 Adsorption Performance of N-Doped Ordered Microporous Carbons Templated from Zeolite HY

2011 ◽  
Vol 284-286 ◽  
pp. 2102-2105 ◽  
Author(s):  
Jin Zhou ◽  
Wen Li ◽  
Shu Ping Zhuo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Deposition ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Microporous Carbons ◽  
Adsorption Performance ◽  
Basic Nitrogen ◽  
Diffraction Patterns ◽  
Very High

Several microporous carbons were prepared by a two-step method using zeolite HY as a template, and were used as CO2 adsorbents. X-ray diffraction patterns present that the structure regularity of the zeolite has been well-replicated by the templated carbons. X-ray photoelectron spectroscopy confirms that the prepared carbons possess abundant nitrogen-containing groups due to the carbon deposition of acetonitrile. The prepared carbons show high CO2 adsorption capacity due to its very high microporous surface area and abundant basic nitrogen-containing groups.

A novel method to bind soybean protein onto the surface of poly(ethylene terephthalate) fabric

2016 ◽  
Vol 87 (4) ◽  
pp. 460-473
Author(s):  
Jianfeng Zhou ◽  
Dandan Zheng ◽  
Fengxiu Zhang ◽  
Guangxian Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ethylene Terephthalate ◽  
Soybean Protein ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pet Fabric ◽  
Poly Ethylene Terephthalate ◽  
Pet Fibers ◽  
Diffraction Patterns ◽  
Poly Ethylene

In this study, –NH2 groups were introduced to a poly(ethylene terephthalate) (PET) fabric to make the fabric hydrophilic and, then, soybean protein was bonded on the surface of the modified PET fabric to obtain a soybean protein/PET composite fabric. The –NH2 groups allowed the soybean protein to be firmly bonded on the surface of the modified PET fabric. Scanning electron microscopy images showed that the surface of each modified PET fiber had a small number of grooves and that there was a thin film on each soybean protein/PET fiber. Attenuated total reflectance Fourier transform infrared spectra demonstrated that the nitrated and reduced PET fibers were introduced –NH2 groups and that there were –CO–NH– groups on the surface of soybean protein/PET fibers. X-ray photoelectron spectroscopy analyses showed that there was a nitrogen element on the modified PET fibers. The X-ray diffraction patterns suggested that the crystal structures of the modified fibers did not change significantly during the modification processes. The thermogravimetry results showed that the thermal stability of soybean protein/PET fiber kept well. The wearability tests indicated that the breaking strength and elasticity of the original fabric were well retained by the modified fabrics. The soybean protein/PET fabric had good levels of hydrophilicity and softness when the binding rate was below 3.0%.

scholarly journals Calcined Co(II)-Triethylenetetramine, Co(II)- Polyaniline-Thiourea as the Cathode Catalyst of Proton Exchanged Membrane Fuel Cell

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3070
Author(s):  
Wen-Yao Huang ◽  
Li-Cheng Jheng ◽  
Tar-Hwa Hsieh ◽  
Ko-Shan Ho ◽  
Yen-Zen Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Linear Sweep Voltammetry ◽  
Conducting Medium ◽  
Membrane Electrode ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Co Catalysts ◽  
Electrode Assemblies ◽  
Diffraction Patterns

Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra clearly reveal the presence of typical carbon nitride and sulfide bonds of the calcined Nitrogen (N)- or Sulfur (S)-doped co-catalysts. Clear (002) and (100) planes of carbon-related X-ray diffraction patterns are found for co-catalysts after calcination, related to the formation of a conducting medium after the calcination of PANI. An increasing intensity ratio of the D to G band of the Raman spectra reveal the doping of N and S elements. More porous surfaces of co-catalysts are found in scanning electronic microscopy (SEM) micropictures when prepared in the presence of both TETA and thiourea (CoNxSyC). Linear sweep voltammetry (LSV) curves show the highest reducing current to be 4 mAcm−2 at 1600 rpm for CoNxSyC, indicating the necessity for both N- and S-doping. The membrane electrode assemblies (MEA) prepared with the cathode made of CoNxSyC produces the highest maximum power density, close to 180 mW cm−2.

Preparation and characterization of graphene oxide/PMMA nanocomposites with amino-terminated vinyl polydimethylsiloxane phase interfaces

2016 ◽  
Vol 36 (9) ◽  
pp. 867-875 ◽  
Author(s):  
Hongyan Li ◽  
Weian Wang ◽  
Lin Cheng ◽  
Jing Li ◽  
Yajing Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Stability ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Bending Strength ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Point Bending ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Amidation Reaction

Abstract Graphene oxide (GO) was prepared by the Hummers method and was grafted by an amino-terminated vinyl polydimethylsiloxane (AP). The AP-modified GO (GO-AP) was incorporated in poly(methylmethacrylate) (PMMA) to prepare nanocomposites. Raman microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis were used to characterize the particles. The mechanical properties, thermal stability, thermal conductivity, and dispersing status of the PMMA-based nanocomposites were also investigated. The results indicated that AP was grafted on the surface of GO via the amidation reaction, and the quantity of the grafted AP was approximately 20 wt% that of GO-AP. With the addition of GO-AP, the three-point bending strength of GO-AP/PMMA increased to approximately 58 MPa, and the dispersion of the particles was also enhanced. GO wrapped by AP could not form thermal conducting networks at the percolation thresholds. The increasing amount of AP prevented the formation of thermal conduction network and decreased the thermal conductivity of the composites. The thermal stability of the composites was affected by three main reasons, and the total effect of the three reasons on thermal stability illustrated a negative trend.

Effect of CuO-TiO2 Eutectic on Thermal and Electrical Conductivities of CaCu3Ti4O12 Ceramics

2016 ◽  
Vol 881 ◽  
pp. 117-122
Author(s):  
Flavia dos Reis Gonçalves ◽  
Daniel Thomazini ◽  
Maria Virginia Gelfuso
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Laser Flash ◽  
Eutectic Phase ◽  
Flash Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical Conductivities ◽  
Diffraction Patterns

In this work, CaCuxTiyO12 ceramics (2.7 ≤ x ≤ 3.3 and 3.25 ≤ y ≤ 4.75), related to excess and deficiency of CuO-TiO2 eutectic phase have been synthesized by coprecipitation method. The crystalline phases in the ceramics were identified by X-ray diffraction patterns, and the pellets have mainly presented CCTO and also exhibited CuO, TiO2 and CaTiO3 as secondary phases. The thermal conductivity of the ceramics was determined using the laser flash method in the temperature range of 300-1000 K. It was observed a decrement in thermal conductivity values as the amount of the eutectic phase decreased. The electrical DC conductivity has been measured by the two-probe method from 300-1000 K and it has been noted that both grain size and amount of eutectic phase influenced the electrical conductivity results.

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