Synthesis and Characterization of Carbon Nanotubes by Using Catalyst LiNi0.5Co0.5O2 on Anodized Alumina Substrate

2009 ◽  
Vol 67 ◽  
pp. 197-202 ◽  
Author(s):  
Kuldeep Rana ◽  
Anjan Sil ◽  
Subrata Ray
Keyword(s):  
Carbon Nanotubes ◽  
Structural Modification ◽  
Pore Diameter ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Anodized Aluminum ◽  
Anodized Aluminum Oxide ◽  
X Ray ◽  
Graphitic Sheet

Carbon nanotubes (CNTs) have been synthesized by chemical decomposition of acetylene gas at 580°C and 650°C using catalyst of LiNi0.5Co0.5O2. The effect of decomposition temperature on structure of the CNTs is that, CNTs grown at 650°C have lower defects concentration and higher crystallinity as compared to that grown at 580°C. The porous anodized aluminum oxide (AAO) template (as substrate), catalyst particles and the CNTs grown were analyzed by FE-SEM. The pore diameter in the template lies in range of 30 - 80 nm. The CNTs have been analyzed by using Raman spectroscopy and X-ray diffraction techniques. The up-shift in G-band of graphitic sheet and larger full width at half maximum of the peak in the Raman spectra of the CNT in comparison to those observed for graphite are indicative of the structural modification. XRD results also indicate the structural modification in CNT based on the fact that d-value becomes 3.42 Å, which is larger than 3.35 Å for graphite. The tube diameters lie in the range of 12 - 50 nm.

scholarly journals Observation and Characterization of Fragile Organometallic Molecules Encapsulated in Single-Wall Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Daisuke Ogawa ◽  
Ryo Kitaura ◽  
Takeshi Saito ◽  
Shinobu Aoyagi ◽  
Eiji Nishibori ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
High Yield ◽  
Single Wall Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Single Wall Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Organometallic Molecules ◽  
X Ray Absorption

Thermally fragile tris(η5-cyclopentadienyl)erbium (ErCp3) molecules are encapsulated in single-wall carbon nanotubes (SWCNTs) with high yield. We realized the encapsulation of ErCp3with high filling ratio by using high quality SWCNTs at an optimized temperature under higher vacuum. Structure determination based on high-resolution transmission electron microscope observations together with the image simulations reveals the presence of almost free rotation of each ErCp3molecule in SWCNTs. The encapsulation is also confirmed by X-ray diffraction. Trivalent character of Er ions (i.e., Er3+) is confirmed by X-ray absorption spectrum.

scholarly journals X Preparation and Characterization of Carbon-Based Composite Nanofibers for Supercapacitor

2017 ◽  
Vol 17 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Dawei Gao ◽  
Lili Wang ◽  
Chunxia Wang ◽  
Yuping Chang ◽  
Pibo Ma
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Electron Microscope ◽  
Surface Area ◽  
Composite Nanofibers ◽  
Carbon Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Abstract Polyacrylonitrile (PAN)/Co(OAc)2/carbon nanotubes (CNTs) composite nanofibers were fabricated via electrospinning with N,N-dimethylformamide (DMF) as solvent, and by carbonization and activation of the above precursor nanofibers, porous carbon composite nanofibers were successfully obtained. Scanning electron microscope, X-ray diffraction, ASAP 2020, and Solartron 1470 were used to characterize the surface morphology, the phase composition, specific surface area, and electrochemical property of the nanofibers, respectively. The result showed that some of the fibers were broken after sintering, and the surface area and pore volume of the porous C/Cu/CNTs were 771 m2/g and 0.347 cm3/g, respectively. The specific capacitance of the composite nanofibers reached up to 210 F/g at the current density of 1.0 A/g. Its energy density and power density were 3.1 Wh/Kg and 2,337 W/Kg, respectively, at the current of 0.5 and 5 mA.

Synthesis and characterization of the pentazolate anion cyclo-N5ˉ in (N5)6(H3O)3(NH4)4Cl

Science ◽  
2017 ◽  
Vol 355 (6323) ◽  
pp. 374-376 ◽  
Author(s):  
Chong Zhang ◽  
Chengguo Sun ◽  
Bingcheng Hu ◽  
Chuanming Yu ◽  
Ming Lu
Keyword(s):  
Thermal Analysis ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Decomposition Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Onset Decomposition Temperature ◽  
The Stability

Pentazole (HN5), an unstable molecular ring comprising five nitrogen atoms, has been of great interest to researchers for the better part of a century. We report the synthesis and characterization of the pentazolate anion stabilized in a (N5)6(H3O)3(NH4)4Cl salt. The anion was generated by direct cleavage of the C–N bond in a multisubstituted arylpentazole using m-chloroperbenzoic acid and ferrous bisglycinate. The structure was confirmed by single-crystal x-ray diffraction analysis, which highlighted stabilization of the cyclo-N5ˉ ring by chloride, ammonium, and hydronium. Thermal analysis indicated the stability of the salt below 117°C on the basis of thermogravimetry-measured onset decomposition temperature.

Characteristics of copper indium diselenide nanowires embedded in porous alumina templates

2010 ◽  
Vol 25 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Piao Liu ◽  
Vijay P. Singh ◽  
Suresh Rajaputra ◽  
Sovannary Phok ◽  
Zhi Chen
Keyword(s):  
Porous Alumina ◽  
Space Charge Density ◽  
Copper Indium Diselenide ◽  
X Ray Diffraction ◽  
Anodized Aluminum ◽  
Anodized Aluminum Oxide ◽  
X Ray ◽  
Acid Bath ◽  
Copper Indium ◽  
Density Values

Vertically aligned nanowire arrays of copper indium diselenide (CuInSe2 or CIS) of controllable diameter and length were fabricated by simultaneously electrodepositing Cu, In, and Se from an acid bath into the pores of anodized aluminum oxide (AAO) formed on top of an aluminum sheet. X-ray diffraction measurements revealed a preferential [112] orientation and the energy dispersive x-ray analysis (EDX) measurements indicated an overall composition close to stoichiometric CuInSe2. Ohmic contact to CIS was formed by depositing a 100 nm thick of gold layer on top, and thus a Schottky diode device of the Au/CIS nanowires/Al configuration was obtained. Analysis of the current–voltage characteristics of these devices yielded diode ideality factor and reverse saturate current density values slightly higher than those reported in the literature for bulk CIS/Al junctions. Capacitance–voltage measurements were performed on the diodes to get the estimates of space charge density and the junction potential.

Preparation and Characterization of Activated Sericite Modified by Fluorosilicate

2012 ◽  
Vol 427 ◽  
pp. 70-76
Author(s):  
Xia Xu ◽  
Hao Ding ◽  
Yue Bo Wang ◽  
Yu Liang ◽  
Wei Jiang
Keyword(s):  
Structural Modification ◽  
Layered Silicate ◽  
Xrd Analysis ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optimal Processing ◽  
Silicate Nanocomposites ◽  
Sodium Fluosilicate

The structure of sericite is stable, and it is hard to prepare polymer layered silicate nanocomposites (PLSN). Therefore, structural modification was employed to activate sericite to reduce the layer charger. The thermal treated sericite (S1) was prepared by thermal modification at 800 for one hour. Then, the resulting product was modified with sodium fluorosilicate, whose effect was characterized by X-ray diffraction (XRD) analysis. The dissolving-out amount of Al3+ of salt-treated product (S2) reached circa 2.55 mg/g at the optimal processing conditions. CEC of S2 was increased to 10.52 meq/100g compared with that of original sericite (4.94 meq/100g). The results of XRD analysis indicated that mica-type phase persisted after salt modification with sodium fluosilicate.

Synthesis and Characterization of Co/SBA-15 Catalysts

2016 ◽  
Vol 881 ◽  
pp. 35-40
Author(s):  
Franciele Oliveira Costa ◽  
Carla Gabriela Azevedo Misael ◽  
André Miranda da Silva ◽  
Bianca Viana de Sousa
Keyword(s):  
Molecular Sieve ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
Average Pore ◽  
Wet Impregnation ◽  
X Ray ◽  
Different Temperatures ◽  
Temperature Programmed

The mesoporous silica SBA-15 molecular sieve has been widely studied due to its unidirectional mesoporous structure, its high average pore diameter, its high thermal and hydrothermal stability and its ability to absorb metal ions, allowing its use as support material for catalysts. This study aimed to synthesize the Co/SBA-15 catalyst, and characterize it through the techniques of X-ray diffraction, temperature programmed reduction (TPR) and scanning electron microscopy (SEM). The SBA-15 support was synthesized from the following molar composition of reaction mixture: 1TEOS: 0.017 P123: 5.7 HCl: 173 H2O: 40 EtOH, and after calcined at 550 °C for 6 hours. The Co/SBA-15 catalyst was prepared by incorporating 10% cobalt by wet impregnation. Through the X-ray diffractograms, it was found that the impregnation has not changed the structure of the material. RTP profiles showed the presence of peaks at different temperatures that may be caused by dispersion of the cobalt.

Comparative Study of Properties of Cellulose Nanofibers From Wheat Straw Obtained by Chemical and Chemi-Mechanical Treatments

2014 ◽  
Author(s):  
Md. Nuruddin ◽  
Mahesh Hosur ◽  
Eldon Triggs ◽  
Shaik Jeelani
Keyword(s):  
Wheat Straw ◽  
Thermal Analyses ◽  
Cellulose Nanofibers ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Scanning Electron Micrograph ◽  
X Ray ◽  
Isolation Techniques ◽  
Transmission Electron

Objective of this work was to compare morphology, crystalline and thermal properties of cellulose nano fibers derived from wheat straw by two different processes (ball milling and acid hydrolysis treatment). The characterization of extracted CNFs was done by Scanning electron micrograph (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). It was found from morphological, crystalline and thermal analyses that isolated cellulose nanofibers have diameter of nano meter ranges (10–25 nm), 68–80 % crystallinity and decomposition temperature of around 284–353° C, depending upon isolation techniques.

scholarly journals Microwave-Assisted Synthesis and Characterization of γ-MnO2 for High-Performance Supercapacitors

2021 ◽  
Author(s):  
Lorena Cuéllar-Herrera ◽  
Elsa Arce-Estrada ◽  
Antonio Romero-Serrano ◽  
José Ortiz-Landeros ◽  
Román Cabrera-Sierra ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
High Performance ◽  
Pore Diameter ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
20 Nm

AbstractTwo hydrothermal techniques under microwave irradiation were used to synthesize γ-MnO2 from 90°C to 150°C in 10−30 min. The first technique is based on reducing KMnO4 with MnSO4, and the second one involves liquid-phase oxidation between MnSO4 and (NH4)2S2O8. The structures and morphologies of the samples were analyzed using X-ray diffraction, scanning electron microscopy, and N2 physisorption measurements. The electrochemical properties were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy. The γ-MnO2 materials obtained by the first technique mainly exhibited nanorods with diameters of 40–60 nm, and the samples obtained by the second technique showed flower-like microspheres with diameters of 1−2 µm; each flower was composed of nanosheets with a thickness of 10−20 nm. The processing time directly depends on the size of the nanorods. The sample synthesized by the first technique at 150°C and 10 min has the highest specific surface area of up to 59.08 m2 g−1 and mean pore diameter of 34.11 nm. Furthermore, this sample exhibits a near-rectangular cyclic voltammetry curves and high specific capacitance of 331.3 F g−1 in 0.1 M Na2SO4 solution at 5 mV s−1 scan rate. Graphic abstract

Preparation of PANI Nanotubes by Template Electrosynthesis

2013 ◽  
Vol 800 ◽  
pp. 406-410
Author(s):  
Bao Song Li ◽  
Wei Wei Zhang
Keyword(s):  
Cyclic Voltammetry ◽  
Influencing Factors ◽  
Pore Diameter ◽  
Electrochemical Polymerization ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outside Diameter ◽  
Polyaniline Nanotubes

Polyaniline nanotubes were prepared by electrochemical polymerization polyaniline within the pores of AAO templates and have been open on one ends. The outside diameter of these tubes is determined by the pore diameter in the template used and that the length of the tube is determined by the thickness of the template. Influencing factors include the polymerization potential, current, scanning rates and numbers, solutions. The characterization of the resulting materials was carried out by UV-vis, X-ray diffraction, cyclic voltammetry, scanning lectron microscopy and conductivity measurements.

scholarly journals Synthesis and characterization of asphalt composite precursors using amorphous rice husk silica

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 194-199 ◽  
Author(s):  
S. Sembiring ◽  
R. Situmeang ◽  
Z. Sembiring
Keyword(s):  
Rice Husk ◽  
Xrd Analysis ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Rice Husk Silica ◽  
X Ray ◽  
Roof Material ◽  
Silica Addition ◽  
Potential Use

Abstract In this research, asphalt composites were produced by mixing asphalt with silica extracted from rice husk, with a ratio of asphalt to silica of 1:0, 1:1.7 and 1:2, and calcined at 150 °C. Development of structures was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), followed by differential thermal analysis (DTA/TGA). The FTIR results showed the presence of Si-OH, C=O, and C-H functional groups, which were associated with asphaltene, carbon, and silica, according to the XRD analysis. The results obtained also indicated the significant effect of rice husk silica addition on phase transformation of asphaltene into silica and carbon, while asphaltene molecules were practically undetected. The presence of silica and carbon resulted in increased decomposition temperature of the sample. Based on these characteristics, the samples were considered as a roof material, suggesting their potential use as a substitute for lightweight steel roof devices.

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