scholarly journals Silicon Carbide-Derived Carbon Prepared by Fused Salt Electrolysis and Electrochemical Performance

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Shuyuan Wang ◽  
Guangjie Shao
Keyword(s):  
Electrochemical Performances ◽  
Constant Voltage ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Carbide Derived Carbon ◽  
Degree Of Order ◽  
A Current

A number of carbide-derived carbon (CDC) samples were successfully synthesized by the electrolysis of SiC powder in molten CaCl2. The electrolysis was conducted at different temperatures (850, 900, and 950°C) for 48 h in argon at an applied constant voltage of 3.1 V. The structure of the resulting carbon is characterized by X-ray diffraction, Raman spectroscopy, and transmission electron microscope techniques. Cyclic voltammetry and galvanostatic charge/discharge measurements are applied to investigate electrochemical performances of the SiC-CDC material. It can be seen that the degree of order of the SiC-CDC increases monotonically along with elevation of reaction temperature, while the highest specific surface area 1137.74 m2/g together with a specific capacitance of 161.27 F/g at a current density 300 mA/g was achieved from sample synthesized at 900°C.

Preparation of Co-Ni Mixed Oxide/Graphene Composite and its Electrochemical Performances as Supercapacitor Material

2017 ◽  
Vol 727 ◽  
pp. 775-780 ◽  
Author(s):  
Yun Long Zhou ◽  
Chen Hao Zhao ◽  
Zhi Biao Hu ◽  
Xue Yan Huang ◽  
Kai Yu Liu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Mixed Oxides ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Graphene Composite ◽  
A Current ◽  
Charge Discharge ◽  
Discharge Test

The Co-Ni mixed oxides/graphene composite has been prepared using the solution based oxidation route. The structures of bare Co-Ni mixed oxides and Co-Ni mixed oxides/graphene composite is clearly studied by X-ray diffraction. The electrochemical properties of Co-Ni mixed oxides/graphene composite are investigated by Cyclic Voltammetry (CV) and galvanostatic charge discharge test. The result shows that, the NiO phase has not been detected in the composite, and the graphene composite delivers a discharge capacity of 353.6 F/g at a current density of 0.32 A g-1.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

Fe–Cr/Al2O3 metal-ceramic composites: Nature and size of the metal particles formed during hydrogen reduction

1994 ◽  
Vol 9 (1) ◽  
pp. 229-235 ◽  
Author(s):  
Ch. Laurent ◽  
J.J. Demai ◽  
A. Rousset ◽  
K.R. Kannan ◽  
C.N.R. Rao
Keyword(s):  
Hydrogen Reduction ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Total Reduction ◽  
Transmission Electron ◽  
Combined Use ◽  
Metal Ceramic ◽  
Different Temperatures ◽  
Metallic Species

Fe-Cr/Al2O3 metal-ceramic composites prepared by hydrogen reduction at different temperatures and for different periods have been investigated by a combined use of Mössbauer spectroscopy, x-ray diffraction, transmission electron microscopy, and energy-dispersive x-ray spectroscopy in order to obtain information on the nature of the metallic species formed. Total reduction of Fe3+ does not occur by increasing the reduction time at 1320 K from 1 to 30 h, and the amount of superparamagnetic metallic species is essentially constant (about 10%). Temperatures higher than 1470 K are needed to achieve nearly total reduction of substitutional Fe3+. Interestingly, iron favors the reduction of chromium. The composition of the Fe-Cr particles is strongly dependent on their size, the Cr content being higher in particles smaller than 10 nm.

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

Effect of Calcination Temperature on the Morphological and Phase Structure of Hydrothermally Synthesized Copper Ion Doped TiO2 Nanotubes

2014 ◽  
Vol 1024 ◽  
pp. 7-10 ◽  
Author(s):  
Mohd Hasmizam Razali ◽  
M.N. Ahmad-Fauzi ◽  
Abdul Rahman Mohamed ◽  
Srimala Sreekantan
Keyword(s):  
Calcination Temperature ◽  
Morphological Evolution ◽  
Copper Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Scanning Electronmicroscopy ◽  
Higher Temperature ◽  
Uniform Diameter

Morphological evolution and phase transformations of copper ion doped TiO2nanotubes after being calcined at different temperatures were studied by field emission scanning electronmicroscopy, transmission electron microscopy, and X-ray diffraction. After calcination at 300°C, the nanotubes with uniform diameter and length wereobtained. At 400°C, the nanotube structures were maintained. Nevertheless the inner tube diameter became narrower, and in same instances disappeared due to aggregation of nanotubes. The copper ion doped TiO2nanotubes then transformed to nanorodsat 500°C and the length of the nanorodsshortens after calcination at 600 °C. When the calcination temperature was further increased to 700°C, the nanorodsdisintegrate to form nanoparticles. On the other hand the phase structures of copper ion doped TiO2nanotubes calcined at 300 and 400 °C were TiO2hexagonal. After calcined at higher temperature (600 and 700°C) they transformed to anatase TiO2(tetragonal).

Ni Doped LiMn2O4 Prepared by a Flameless Combustion Synthesis

2012 ◽  
Vol 625 ◽  
pp. 251-254 ◽  
Author(s):  
Gui Yang Liu ◽  
Bao Sen Wang ◽  
Ying He ◽  
Jun Ming Guo
Keyword(s):  
Combustion Synthesis ◽  
Raw Materials ◽  
Synthesis Method ◽  
Solution Combustion Synthesis ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Solution Combustion ◽  
Limn2o4 Spinel ◽  
X Ray

In this paper, LiNixMn2−xO4 materials were prepared by solution combustion synthesis method using acetic salts as raw materials and acetic acid as fuel. The phase structures are characterized by X-ray diffraction (XRD). Electrochemical performances of the materials are investigated by galvanostatic charge/discharge methods. XRD results revealed that the main phase of the products with increasing Ni3+ content is LiMn2O4, and there is a trace amount of Mn3O4 found in the product with Ni3+ content of 0.05. Electrochemical experiments showed that the capacity and the cyclability of the LiNixMn2−xO4 materials decrease with increasing Ni3+ content. Ni3+ doping has no significantly improvement for the capacity and the cyclability of the LiMn2O4 spinel.

Synthesis of NiFe2O4 Nanoparticles and its Supercapacitive Properties

2013 ◽  
Vol 275-277 ◽  
pp. 1733-1736 ◽  
Author(s):  
Zi Tao Yang ◽  
Bo Wen Cheng ◽  
Yong Nan Zhao
Keyword(s):  
Water Solution ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Transmission Electron ◽  
Nife2o4 Nanoparticles ◽  
Diffraction Peaks ◽  
Xrd Patterns ◽  
Charge Discharge

NiFe2O4 nanoparticles was successfully synthesized by hydrothermal decomposition of a gel of Ni-Fe-EG (EG=ethylene glycol) in water solution. The crystal structure and morphologies of the products were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). All the diffraction peaks in XRD patterns revealed that the as-synthesized nanoparticles were pure NiFe2O4. TEM images disclosed that the particle sizes of the nanoparticles were in the range of 10 − 25nm. The cyclic voltammetry (CV) and galvanostatic charge/discharge results tested in 6M KOH solution revealed a double layer capacitive behavior and a revisable charge/discharge property.

The Synthesis and Electrochemical Performance of LiV3O8 Cathode with Lanthanum-Doped

2012 ◽  
Vol 560-561 ◽  
pp. 860-863
Author(s):  
Fang Hu ◽  
Mo Ran Sun ◽  
Yu Sheng Wu ◽  
Chun Hua Zhang
Keyword(s):  
Sol Gel ◽  
Discharge Voltage ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Cyclic Voltammetric ◽  
Voltage Range ◽  
X Ray ◽  
Voltage Plateau ◽  
First Discharge Capacity

Li1-xLaxV3O8 cathode materials has been synthesized by pechini sol-gel method. The electrochemical performances of Li1-xLaxV3O8(x=0-0.05) have been studied by X-ray diffraction (XRD), galvanostatic charge-discharge, and cyclic voltammetric (CV). The results showed that the optimal content of the La3+ doping in LiV3O8 was x=0.01, and the first discharge capacity of Li0.99La0.01V3O8 sample in the voltage range of 2.0-4.0V was 230mAhg-1, which was much higher than that of LiV3O8 (200mAhg-1). The Li0.99La0.01V3O8 cathode also showed higher discharge voltage plateau than LiV3O8 cathode from the CV curves.

A new high-temperature inorganic–organic proton conductor: lanthanum sulfophenyl phosphate

2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Ming-Feng Song ◽  
Zhong-Fang Li ◽  
Guo-Hong Liu ◽  
Su-Wen Wang ◽  
Xiao-Yan Yin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Layered Structure ◽  
Proton Conductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Different Temperatures ◽  
Thermal Stability Of

AbstractLanthanum sulfophenyl phosphate (LaSPP) was synthesized by m-sulfophenyl phosphonic acid and lanthanum nitrate. UV-Vis spectrophotometry and Fourier-transform infrared spectroscopy indicate that the desired product was obtained and its elementary composition and typical layered structure were determined by energy dispersive X-ray spectroscopy and scanning electron microscopy. Transmission electron microscopy (TEM) proved its typical layered structure and X-ray diffraction spectroscopy indicated its good crystallinity and the interlayer distance of about 15.67 Å , which matches the value obtained by TEM (2.0 nm). Thermogravimetry and differential thermal analysis revealed good thermal stability of LaSPP. Proton conductivity of LaSPP was measured at different temperatures and relative humidities (RH), reaching values of 0.123 S cm

scholarly journals Biochar-Supported FeS/Fe3O4 Composite for Catalyzed Fenton-Type Degradation of Ciprofloxacin

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1062 ◽  
Author(s):  
Yue Wang ◽  
Xiaoxiao Zhu ◽  
Dongqing Feng ◽  
Anthony K. Hodge ◽  
Liujiang Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Iron Sulfide ◽  
Magnetic Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Fe3o4 ◽  
Different Temperatures ◽  
Cost Efficient

The Fenton-type oxidation catalyzed by iron minerals is a cost-efficient and environment-friendly technology for the degradation of organic pollutants in water, but their catalytic activity needs to be enhanced. In this work, a novel biochar-supported composite containing both iron sulfide and iron oxide was prepared, and used for catalytic degradation of the antibiotic ciprofloxacin through Fenton-type reactions. Dispersion of FeS/Fe3O4 nanoparticles was observed with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). Formation of ferrous sulfide (FeS) and magnetite (Fe3O4) in the composite was validated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Ciprofloxacin (initial concentration = 20 mg/L) was completely degraded within 45 min in the system catalyzed by this biochar-supported magnetic composite at a dosage of 1.0 g/L. Hydroxyl radicals (·OH) were proved to be the major reactive species contributing to the degradation reaction. The biochar increased the production of ·OH, but decreased the consumption of H2O2, and helped transform Fe3+ into Fe2+, according to the comparison studies using the unsupported FeS/Fe3O4 as the catalyst. All the three biochars prepared by pyrolysis at different temperatures (400, 500 and 600 °C) were capable for enhancing the reactivity of the iron compound catalyst.

Sign in / Sign up

Export Citation Format

Share Document