Multifunctionality exploration on NiCo2O4–rGO nanocomposites: Photochemical water oxidation, methanol electro-oxidation and asymmetric supercapacitor applications

2021 ◽  
Author(s):  
Vikash Gajraj ◽  
Alesh Kumar ◽  
Ekta Dadarwal ◽  
Rahul Kaushik ◽  
Amilan Jose Devadoss ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Hydrothermal Method ◽  
Water Oxidation ◽  
Asymmetric Supercapacitor ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Electron Microscopies ◽  
Electro Oxidation ◽  
Supercapacitor Applications

Different weight percentages of NiCo2O4–rGO nanocomposites were prepared via a facile hydrothermal method. The prepared nanocomposites were structurally and morphologically characterized by X-ray diffraction, Raman spectroscopy and electron microscopies. The...

Facile hydrothermal synthesis of Fe3O4 nanoparticle and effect of crystallinity on performances for supercapacitor

2019 ◽  
Vol 12 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Yue Xu ◽  
Ying Zhang ◽  
Xiaolan Song ◽  
Hanjun Liu
Keyword(s):  
Hydrothermal Method ◽  
Reaction Times ◽  
Amorphous Structure ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Oxide Electrode ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Pseudocapacitive Behavior ◽  
Adsorption Desorption

Fe3O4 nanoparticles were synthesized by a facile hydrothermal method using triethanolamine. Effects of reaction times (2–8[Formula: see text]h) on crystallinity and electrochemical performances of Fe3O4 were investigated. Samples were analyzed by X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, scanning electron microscope, galvanostatic charge/discharge, and cyclic voltammetry. Results showed that the crystallinity of Fe3O4 was increased with hydrothermal time, and the sample prepared at 2[Formula: see text]h displayed amorphous structure with small grain size and large surface area of 165.0[Formula: see text]m2[Formula: see text]g[Formula: see text]. The sample exhibited typical pseudocapacitive behavior with capacitance of 383.2[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5 Ag[Formula: see text] in Na2SO3 electrolyte. After 2000 cycles, the capacitance retention of Fe3O4 at 2[Formula: see text]h was recorded as 83.6%, much higher than 26.3% for sample at 8[Formula: see text]h. It indicated that hydrothermal method was an effective approach to obtain amorphous Fe3O4, implying the potential application for preparing metal oxide electrode for supercapacitors.

Hierarchically Porous Carbon/MnO2 Nanocomposites as High-Performance Electrode for Asymmetric Supercapacitors

2014 ◽  
Vol 1070-1072 ◽  
pp. 530-533
Author(s):  
Yu Rong Liu ◽  
Jia Liu
Keyword(s):  
Porous Carbon ◽  
High Performance ◽  
Asymmetric Supercapacitor ◽  
X Ray Diffraction ◽  
Excellent Performance ◽  
Asymmetric Supercapacitors ◽  
Hierarchically Porous ◽  
X Ray ◽  
Supercapacitor Applications ◽  
Scanning Electron

Hierarchically porous carbon (HPC)/MnO2 nanocomposites were fabricated for asymmetric supercapacitor applications. The microstructures of HPC/MnO2 nanocomposites were characterized by X-ray diffraction and scanning electron microscopy. The asymmetric supercapacitor consisting of a HPC/MnO2 cathode and a HPC anode shows an excellent performance with energy density and power density of 23.8 Wh kg-1 and 12.5 kW kg-1, respectively. In addition, the asymmetric supercapacitor exhibits an excellent cycle life with 91% retention of capacitance after 1000 cycles.

scholarly journals TAILORING THE STRUCTURE AND MORPHOLOGY OF WO3 NANOSTRUCTURES BY HYDROTHERMAL METHOD

2018 ◽  
Vol 56 (1A) ◽  
pp. 127
Author(s):  
Luu Thi Lan Anh
Keyword(s):  
Raman Spectroscopy ◽  
Hydrothermal Method ◽  
Synthesis Method ◽  
Precursor Solution ◽  
Acid Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Wo3 Nanostructures

Tungsten oxide nanostructures were synthesized by hydrothermal and acid precipitation (hydrothermal at room temperature) methods without using any supporting agent or structure-directing reactant. The morphology and crystalline structure of nanostructures strongly depended on pH of the precursor solution and synthesis method. With pH = -1.0, using acid precipitation method, orthorhombic nanoplate was observed. Using hydrothermal method, with the pH = - 1.0, we obtained directly stable monoclinic nanoparticle WO3. With pH = 1.1, the mixing of nanoparticle and nanorod with the hexagonal frame was acquired. When pH reaches to 1.7, only bundle of hexagonal nanorods was observed.  To characterize the morphology and structure of tungsten nanostructures, we used Field Emission Scanning Electron Microscopy, X-ray diffraction, and micro Raman spectroscopy. The micro Raman spectroscopy was used to support the X-ray diffraction analysis. These results imply that adjusting pH is an efficient and promising method to manipulate both morphology and crystal structure of WO3 nanostructure for selective applications.   

Raman spectroscopy and X-ray diffraction of lithium niobate at temperatures up to 1300○-4.80pt○C

2005 ◽  
Vol 126 ◽  
pp. 101-105 ◽  
Author(s):  
B. Moulin ◽  
L. Hennet ◽  
D. Thiaudière ◽  
P. Melin ◽  
P. Simon
Keyword(s):  
Raman Spectroscopy ◽  
Lithium Niobate ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Structural and Raman Vibrational Studies ofCeO2-Bi2O3Oxide System

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
L. Bourja ◽  
B. Bakiz ◽  
A. Benlhachemi ◽  
M. Ezahri ◽  
J. C. Valmalette ◽  
...  
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Phase Changes ◽  
Phase System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vibrational Studies ◽  
Coprecipitation Route

A series of ceramics samples belonging to theCeO2-Bi2O3phase system have been prepared via a coprecipitation route. The crystallized phases were obtained by heating the solid precursors at600∘Cfor 6 hours, then quenching the samples. X-ray diffraction analyses show that forx<0.20a solid solutionCe1−xBixO2−x/2with fluorine structure is formed. For x ranging between 0.25 and 0.7, a tetragonalβ′phase coexisting with the FCC solid solution is observed. For x ranging between 0.8 and 0.9, a new tetragonalβphase appears. Theβ′phase is postulated to be a superstructure of theβphase. Finally, close tox=1, the classical monoclinicα Bi2O3structure is observed. Raman spectroscopy confirms the existence of the phase changes as x varies between 0 and 1.

Cetyltrimethylammonium bromide- and ethylene glycol-assisted preparation of mono-dispersed indium oxide nanoparticles using hydrothermal method

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Selvakumar Dhanasingh ◽  
Dharmaraj Nallasamy ◽  
Saravanan Padmanapan ◽  
Vinod Padaki
Keyword(s):  
Ethylene Glycol ◽  
Hydrothermal Method ◽  
Indium Oxide ◽  
Cetyltrimethylammonium Bromide ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractThe influence of cetyltrimethylammonium bromide and ethylene glycol on the size and dispersion of indium oxide nanoparticles prepared under hydrothermal conditions was investigated. The precursor compound, indium hydroxide, obtained by the hydrothermal method in the absence as well as the presence of cetyltrimethylammonium bromide, was converted to indium oxide by sintering at 400°C. The formation of nanoscale indium oxide upon sintering was ascertained by the characteristic infrared adsorption bands and X-ray diffraction patterns of indium oxide. Transmission electron microscopy and band gap values confirmed that the cetyltrimethylammonium bromide facilitated the formation of indium oxide nanoparticles smaller in size and narrower in distribution than those prepared without the assistance of cetyltrimethylammonium bromide.

Microscintillator of Ce Doped β-NaLuF4 in Uniform Hexagonal Prism Morphology by a Facile Hydrothermal Method

2014 ◽  
Vol 541-542 ◽  
pp. 220-224
Author(s):  
Li Sha Liu ◽  
Hao Hong Chen ◽  
Bi Qiu Liu ◽  
Bin Tang ◽  
Zhi Jia Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hexagonal Phase ◽  
Broad Band ◽  
High Energy ◽  
Hexagonal Prism ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Strong Broad Band ◽  
Broad Band Emission ◽  
Band Emission

To explore micro-or nanoscintillator with a controllable architecture, a novel facile hydrothermal method easy for commercial run was used to synthesize pure and Ce doped β-NaLuF4 microcrystals at 453K. The morphology of uniform hexagonal prism with 3.3μm in diameter and 1.4 μm in thickness, respectively, is presented by the results of scanning electron microscopy (SEM). Powder X-ray diffraction (PXRD) patterns show the products are both pure hexagonal phase. Different from the undoped product without any irradiation, the Ce doped product has given strong broad band emission attributed to 5d4f transition of Ce3+, which can be potentially used as scintillator for biomedical imaging and detectors for high energy such as X-ray and γray. This synthetical strategy extends the understanding about nanomaterial chemistry and can be also useful for other systems such as fluorides, oxides and sulfides.

scholarly journals Amorphization of a proposed sorbent of strontium, brushite, CaHPO4•2H2O, studied by X-ray diffraction and Raman spectroscopy

2021 ◽  
Vol 545 ◽  
pp. 152751
Author(s):  
Marie-Noëlle de Noirfontaine ◽  
Enrique Garcia-Caurel ◽  
Daniel Funes-Hernando ◽  
Mireille Courtial ◽  
Sandrine Tusseau-Nenez ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray

High pressure structural study of β-Ti3O5: X-ray diffraction and Raman spectroscopy

2012 ◽  
Vol 192 ◽  
pp. 356-359 ◽  
Author(s):  
Ye Wu ◽  
Qian Zhang ◽  
Xiang Wu ◽  
Shan Qin ◽  
Jing Liu
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Structural Study ◽  
X Ray Diffraction ◽  
X Ray
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