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).

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 Aging Treatment on Damping Capacity in Mncunife Alloy

2012 ◽  
Vol 246-247 ◽  
pp. 1158-1162
Author(s):  
Xu Fu ◽  
Ning Li ◽  
Yu Hua Wen ◽  
Jing Teng ◽  
Ying Zhang
Keyword(s):  
Electron Microscope ◽  
Aging Treatment ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The Relationship

M2052 alloys with various aging treatments are obtained in order to investigate the relationship between aging treatment and damping capacity by the torsion pendulum, X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results show that M2052 can obtain high damping capacity (δ>0.2) when aged at a range from 400°C to 450°C, and the damping capacity after aged at a lower temperature is higher than that aged at a higher temperature for the maximum values. TEM and XRD results show that fcc-fct transformation occurs after aging treatment. The volumes of fct structures are one of reason to affect the damping capacity in M2052 alloy. The better understanding aging treatment could promote the applications of M2052 alloy.

Structural investigation of tungsten oxide nanowires by X-ray diffraction and transmission electron microscopy

2010 ◽  
Vol 25 (S1) ◽  
pp. S22-S24 ◽  
Author(s):  
Shibin Sun ◽  
Suyuan Sun ◽  
Zhenjiang Li
Keyword(s):  
Tungsten Oxide ◽  
Structural Investigation ◽  
Morphological Evolution ◽  
Crystal Defects ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Oxide Nanowires ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

X-ray diffraction, selected area electron diffraction, and high-resolution transmission electron microscope techniques were used to investigate the crystalline structures of one-dimensional tungsten oxide nanowires prepared by the hydrothermal method. The as-synthesized products were found to exhibit increasing crystallinity with increasing reaction time, and tungsten oxide nanowires have crystalline defects, including stacking faults, dislocations, and vacancies. The results on the crystal defects help us to obtain a better understanding of the temperature-dependent morphological evolution of the ultrathin nanowires synthesized under different thermal processes.

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.

Zinc Oxide Nanostructures Synthesized by Thermal Oxidation of Zinc Powder on Si Substrate

2013 ◽  
Vol 328 ◽  
pp. 710-714 ◽  
Author(s):  
Suttinart Noothongkaew ◽  
Supakorn Pukird ◽  
Worasak Sukkabot ◽  
Bualoy Kasemporn ◽  
Prayoon Songsiririttikul ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Oxidation Process ◽  
Zinc Powder ◽  
Zinc Oxide Nanostructures ◽  
X Ray Diffraction ◽  
Average Width ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Different Temperatures ◽  
Higher Temperature

ZnO nanowhiskers were formed by a simple oxidation of metallic zinc powder 99.9% at different temperatures from 400-900 °C for 2 hours on the silicon substrate. The result can be obtained after the thermal oxidation process, the ZnO nanowhiskers with different morphologies at different temperatures in which these morphologies and composition of ZnO nanostructures were characterized by scanning electron microscope, (SEM) and X-ray diffraction, XRD. It was found that the products were nanowhiskers, the structure are triangular shapes with average width of 10-50 nm at the root, 10-30 nm at the tip and length in the range of 1-3 μm was observed by SEM. Temperature in the range of 600-700 °C was suitable for the preparation of ZnO nanowhiskers. At higher temperature of 800 °C, the concentrations of ZnO structures become lower and stronger. At the oxidized temperature of 900 °C, ZnO nanowhiskers were not found and surface morphology become to porous. These results indicate that the oxidation rate is faster than the diffusion rate of Zn vapor on the surface of ZnO nuclei.

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.

Charge transport measurements in compressed bulk graphene oxide

2020 ◽  
Vol 111 (7) ◽  
pp. 552-558
Author(s):  
Boateng Onwona-Agyeman ◽  
Yong Sun ◽  
Hayami Hattori
Keyword(s):  
Graphene Oxide ◽  
Charge Transport ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Tunneling Mechanism ◽  
Transport Measurements ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Surface Morphologies

Abstract Charge transport measurements in compressed bulk graphene oxide (GO) have been studied within the temperature range 15-450 K. Structural properties and surface morphologies of the bulk compressed GO were studied using X-ray diffraction and transmission electron microscopy. Raman and X-ray photoelectron spectroscopies were also used to confirm the presence of graphitic phases and the various functional groups in the GO, respectively. Current-voltage characteristics of the GO measured with gold (Au) electrodes at different temperatures showed no Schottky barrier at the Au/GO interface. At low temperatures and low bias voltages, the electron transport through the compressed GO sample showed no significant voltage dependence, which is consistent with a direct tunneling mechanism at all the bias voltages (0.01 -1.0 V). It was also observed that no Fowler- Nordheim transport mechanism occurred within this bias voltage range.

Upcycling of Polystyrene Waste Plastics to High Value Carbon by Thermal Decomposition

2021 ◽  
Vol 897 ◽  
pp. 103-108
Author(s):  
Kenneth Mensah ◽  
Hatem Mahmoud ◽  
Manabu Fujii ◽  
Hassan Shokry
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Waste Plastics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Environmental Threats ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Polystyrene Waste ◽  
Synthesized Materials

Globally, the adverse environmental impact of waste plastics is of increasing concern. Most plastics are naturally non-degradable, thus imposes serious environmental threats, especially, to marine life. Upcycling such waste into valuable contents is an effective approach to managing waste plastics. In this study, graphene is synthesized from waste polystyrene (PS) by thermal decomposition at different temperatures (500, 600, 700, 800, 900 and 1000 °C) for two hours reaction time in a stainless steel autoclave. The synthesized materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy-disperse X-ray analysis (EDS) and surface area by using Brunauer–Emmett–Teller (BET). The yield of the product materials was investigated and optimized against the temperature. The synthesized graphene is considered a promising material for many applications, especially in environmental applications.

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