scholarly journals Synthesis and electrochemical properties of Fe2O3@C composite

2018 ◽  
Vol 34 (4) ◽  
Author(s):  
Thi Hang Bui
Keyword(s):  
Electrochemical Properties ◽  
Hydrothermal Method ◽  
Reaction Rate ◽  
Negative Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
One Step ◽  
Air Battery ◽  
Cv Measurements ◽  
Scanning Electron

Fe2O3@C material was prepared by one-step hydrothermal method for use as a negative electrode in an iron-air battery. The structure of Fe2O3@C was determined by X-ray diffraction (XRD) measurement while their morphology was observed by scanning electron microscopy (SEM). The electrochemical properties of the Fe2O3@C electrode in alkaline solution were investigated using cyclic voltammetry (CV) measurement. The results showed that Fe2O3@C material with α-Fe2O3 structure and amorphous carbon were successfully synthesized by one-step hydrothermal method. CV measurements indicate that the redox reaction rate of the Fe2O3@C electrode is higher than that of the Fe2O3@AB electrode using commercial Fe2O3 and AB (Acetylene Black Carbon).

scholarly journals Effect of Surfactant Addition on Bi2Te3 Nanostructures Synthesized by Hydrothermal Method

2017 ◽  
Vol 62 (2) ◽  
pp. 1005-1010 ◽  
Author(s):  
Peyala Dharmaiah ◽  
C.H. Lee ◽  
B. Madavali ◽  
Soon-Jik Hong
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Figure Of Merit ◽  
Bulk Sample ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coarse Grains ◽  
Scanning Electron ◽  
Nanostructured Sample

AbstractIn the present work, we have prepared Bi2Te3nanostructures with different morphologies such as nano-spherical, nanoplates and nanoflakes obtained using various surfactant additions (EG, PVP, and EDTA) by a hydrothermal method. The shape of the nanoparticles can be controlled by addition of surfactants. The samples were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that the minority BiOCl phase disappears after maintained pH at 10 with EG as surfactant. SEM bulk microstructure reveals that the sample consists of fine and coarse grains. Temperature dependence of thermoelectric properties of the nanostructured bulk sample was investigated in the range of 300-450K. The presence of nanograins in the bulk sample exhibits a reduction of thermal conductivity and less effect on electrical conductivity. As a result, a figure of merit of the sintered bulk sample reached 0.2 at 400 K. A maximum micro Vickers hardness of 102 Hv was obtained for the nanostructured sample, which was higher than the other reported results.

The Influence of the Addition of rGO and CNT on the Electrochemical Properties of the Batteries the LaNi-Based Battery Alloys

2020 ◽  
Vol 1012 ◽  
pp. 153-157
Author(s):  
Edson Pereira Soares ◽  
J.C.S. Filho ◽  
J.C.S. Casini ◽  
R.N. Faria ◽  
Hidetoshi Takiishi
Keyword(s):  
Electron Microscopy ◽  
Discharge Capacity ◽  
Cast Alloy ◽  
Negative Electrode ◽  
Cyclic Stability ◽  
X Ray Diffraction ◽  
Electrochemical Test ◽  
X Ray ◽  
Reduced Graphene ◽  
Scanning Electron

In this article the results of the negative electrode performance produced by La0.7Mg0.3Al0.3Mn0.4Co0.5Ni3.8 as-cast alloy adding 1 to 10% of carbon nanotube (CNT) or reduced graphene oxide (rGO) were investigated as Ni-MH batteries. The as cast alloy were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The CNT and rGO were characterized by high resolution SEM-FEG. The discharge capacity obtained during the electrochemical characterization showed that in the addition of 1% rGO the discharge capacity was 332 mAh and 1% CNT 364 mAh , being that the rGO batteries maintaining better cyclic stability during the electrochemical test.

Characterization of Lead Zirconate Titanate Powders Prepared by a Hydrothermal Method

2005 ◽  
Vol 902 ◽  
Author(s):  
Lingjuan Che ◽  
Yongping Ding ◽  
Jinrong Cheng ◽  
Chao Chen ◽  
Zhongyan Meng
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Method ◽  
Lead Zirconate Titanate ◽  
Fourier Transformation ◽  
Lead Zirconate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconate Titanate ◽  
Scanning Electron

AbstractLead Zirconate Titanate (PZT) powders have been synthesized by a hydrothermal method at the processing temperatures of 120-220 °C for 1.5-50 hours, based on the reaction of Pb(CH3COOH)2·3H2O, ZrOCl2·8H2O, Ti(C4H9O)4 and KOH. Hydrothermally treated PZT powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transformation infrared (FTIR) techniques respectively. The influences of hydrothermal synthesize conditions on the crystalline structure and the morphology of PZT particles were investigated. Crystallized PZT powders could be synthesized at the KOH concentration of >2.5 mol/l.

Solvothermal Synthesis and Electrochemical Properties of Hairball-Like Bismuth Trisulphide Microcrystallines

2011 ◽  
Vol 233-235 ◽  
pp. 2289-2293
Author(s):  
Pin Jiang Li ◽  
Wen Jun Fa ◽  
Yan Ge Zhang ◽  
Bao Jun Huang ◽  
Yi Dong Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Growth Process ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Scanning Electron

Hairball-like bismuth trisulphide microcrystallines has been successfully prepared via one step solvothermal process and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) techniques. The morphologies of the Bi2S3 microcrystallines were influenced by reaction time, temperature, the mole ratio of the reactants and concentration of starting materials, and the growth process has been proposed. The electrochemical behavior of Bi2S3 was investigated using the cyclic voltammetry.

Effects of Reductive Conditions on the Electrochemical Properties of LiFePO4/C Derived by Fe3+ Sources

2014 ◽  
Vol 1081 ◽  
pp. 313-317
Author(s):  
Yan Wen Lu ◽  
Yu Ge ◽  
Yue Feng Tang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Sintering Atmosphere ◽  
X Ray ◽  
Electrochemical Capacity ◽  
One Step ◽  
Scanning Electron

A one-step carbon thermal method was used to prepare LiFePO4/C particles by using normal Fe2O3, LiH2PO4and sucrose as raw materials. The effect of H2content in the sintering atmosphere of N2on the morphology and the electrochemical performance were investigated. LiFePO4/C materials were characterized by X-ray diffraction, scanning electron microscopy and the elemental analyzer. The results show that the precursor sintering under the atmosphere of 8%H2+N2exhibits the highest electrochemical capacity (162.3 mAh/g at 0.1C) .

scholarly journals EFFECT OF HYDROTHERMAL TEMPERATURE ON SYNTHESIS OF HYDROXYAPATITE FROM LIMESTONE VIA HYDROTHERMAL METHOD

2018 ◽  
Vol 10 (1) ◽  
pp. 136 ◽  
Author(s):  
Novesar Jamarun ◽  
Asregi Asril ◽  
Zulhadjri Zilfa ◽  
Upita Septiani
Keyword(s):  
Hydrothermal Method ◽  
Crystal Size ◽  
Spherical Shape ◽  
X Ray Diffraction ◽  
Hydrogen Phosphate ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Nano Powder ◽  
Diammonium Hydrogen ◽  
Scanning Electron

Objective: In this study, the effect of hydrothermal temperature on the synthesis of hydroxyapatite (HAp) from limestone was investigated.Methods: Precursors of limestone (CaCO3) and diammonium hydrogen phosphate ((NH4)2HPO4) with Ca/P ratio of 1.67 was mixed at pH 10 in order to synthesize hydroxyapatite by hydrothermal method. The solution was hydrothermally treated in an autoclave at various temperatures of 120, 160 and 200 °C for 24 h. Nano powder formed was then characterized.Results: The hydroxyapatite obtained by hydrothermal method at various temperatures was characterized. The analysis of Fourier Transform Infrared (FTIR) revealed that HAp had phosphate (PO43-) and hydroxyl (O-H) groups although carbonate (CO32-) group remained. X-Ray Diffraction (XRD) revealed that the size of nanosize crystals was formed and then provided a large surface area. Scanning Electron Microscopy (SEM) results showed that HAp had a spherical shape. There was more agglomeration at 200 °C than at 160 °C. The ratio of the results of Energy Dispersive X-ray (EDX) analysis in 160 °C was 1.95 and at 200 °C was 1.71Conclusion: The hydroxyapatite prepared at a temperature of 200 °C had smaller crystal size than the hydroxyapatite prepared at the temperatures of 120 and 160 °C. SEM pictures showed that the nanoparticle hydroxyapatite had a spherical shape.

Preparation and Characterizations of a-Fe2O3 Nanorods and their Properties

2016 ◽  
Vol 852 ◽  
pp. 346-348
Author(s):  
Hong Cai ◽  
Qing Bo Du ◽  
Ji Gui Xu ◽  
Hong Wei Shi ◽  
Jun Zhu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Magnetic Measurement ◽  
Remnant Magnetization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Fundamental Research ◽  
Scanning Electron

a-Fe2O3 nanorods over large areas were successfully synthesized by hydrothermal method, using FeCl3 as iron source and PVP as surfactant. The as-synthesized a-Fe2O3 nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and magnetic measurement system (SQUID-VSM) . The results show that the nanorods prepared by hydrothermal method with the diameter of about 70 nm and the length of about 300 nm. The magnetic properties of the synthesized nanorods were studied, and the remnant magnetization and coercivity of the α-Fe2O3 nanorods at 300K are found to be 0.07emu/g and 2300Oe, respectively. The a-Fe2O3 nanorods reported here may have opportunities for both fundamental research and technological applications.

Phase Composition and Morphology of Pottery Stone Microcrystalline Powders Synthesized by Hydrothermal Method

2013 ◽  
Vol 664 ◽  
pp. 620-624
Author(s):  
Amnouy Larpkasemsuk ◽  
Saowaroj Chuayjuljit ◽  
Dujreutai Pongkao Kashima
Keyword(s):  
Phase Composition ◽  
Hydrothermal Method ◽  
X Ray Diffraction ◽  
Major Phase ◽  
X Ray ◽  
Polyhedral Particles ◽  
Naoh Solution ◽  
Xrd Patterns ◽  
Aluminium Silicates ◽  
Scanning Electron

Pottery stone (PTS) microcrystalline powders were synthesized by a hydrothermal method using two concentrations of NaOH solution (2 M and 4 M) at 60, 80 and 120°C for 8 h in a Teflon- lined stainless steel autoclave. The phase composition and morphology of the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The major phase compositions of the as-prepared PTS powders appeared in the XRD patterns are all silicate compounds such as tridymite, crystobalite, quartz, feldspar, albite, sodium silicate, analcime, hydroxyl-cancrinite and sodium aluminium silicates, depending on the NaOH concentration and the reaction temperature. Moreover, SEM micrographs showed the spherical polyhedral particles ranging from 8 to 14 µm in diameters and needle-like particles with a mean aspect ratio of 5.7 that obtained by the hydrothermal treatment operated at 120°C using 2 M and 4 M of NaOH, respectively.

A POROUS VANADIUM PENTOXIDE MATERIAL AND ITS ELECTROCHEMICAL PROPERTIES IN AQUEOUS ELECTROLYTE

2011 ◽  
Vol 04 (01) ◽  
pp. 61-64 ◽  
Author(s):  
ZHAOHUI LI ◽  
JIAOJUN TANG ◽  
JIE YANG ◽  
CHENG CHENG ◽  
QIZHEN XIAO ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Vanadium Pentoxide ◽  
Aqueous Electrolyte ◽  
Sol Gel ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Cycling Performances ◽  
Scanning Electron

A porous vanadium pentoxide ( V2O5 ) material was prepared through a facile sol-gel route using β-cyclodextrin (β-CD) as template reagent. Its crystal structure and morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively. The electrochemical properties of the as-prepared V2O5 in 1.0 mol l-1 Li2SO4 aqueous electrolyte were investigated by galvanostatic charging/discharging and cyclic voltammetry. The results revealed that the porous V2O5 could deliver the average capacities of 67, 54 and 42 mAh g-1 at the rates of 0.1, 0.5 and 2 C, respectively. The cycling performances of the V2O5/LiMn2O4 cells suggested that the porous V2O5 material could be used as an anode material for aqueous rechargeable lithium-ion batteries.

The Synthesis and Characterization of NiCo2O4 Nanoparticles

2012 ◽  
Vol 512-515 ◽  
pp. 2467-2470 ◽  
Author(s):  
Hong Xiao Zhao ◽  
Bao Ming He ◽  
Jing Li ◽  
Hui Min Jia ◽  
Li Wei Mi
Keyword(s):  
Thermal Decomposition ◽  
Hydrothermal Method ◽  
Physical Adsorption ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Preparation Methods ◽  
Oxalate Precursor ◽  
X Ray ◽  
Scanning Electron

In this paper, NiCo2O4 nanoparticles were synthesized by three different methods. The applied preparation methods in this research are thermal decomposition of a mixed oxalate precursor, combustion synthesis and hydrothermal method. The crystalline phase, morphology and specific surface area (BET) of the resultant samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and nitrogen physical adsorption, respectively. The research found that the hydrothermal method is a promising method to prepare NiCo2O4 nanoparticles.

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