Improved electrochemical behavior of metal oxides-based nanocomposites for supercapacitor

2019 ◽  
Vol 12 (05) ◽  
pp. 1950064 ◽  
Author(s):  
P. Anandhi ◽  
V. Jawahar Senthil Kumar ◽  
S. Harikrishnan
Keyword(s):  
Electron Microscopy ◽  
Electrode Material ◽  
Sol Gel ◽  
Active Material ◽  
Galvanostatic Charge ◽  
Electrochemical Behaviors ◽  
Transmission Electron ◽  
Gel Technique ◽  
Promising Electrode Material ◽  
Charge Discharge

This paper investigates the synthesis and enhanced electrochemical behaviors of ZnO and NiO/ZnO nanocomposites for electrode material of supercapacitors. ZnO and NiO/ZnO nanocomposites were produced via sol–gel technique. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to determine the size and structure of as-synthesized nanomaterials, respectively. The capacitive behavior and charge–discharge characteristics of the electrode using ZnO and NiO/ZnO nanocomposites (as active material) were individually probed with the help of cyclic voltammetry (CV) and galvanostatic charge-discharge tests, respectively. The specific capacitance of nanocomposites-based electrode calculated from galvanostatic charge-discharge tests was 469[Formula: see text]F [Formula: see text] at the scan rate of 1[Formula: see text]mA [Formula: see text] in 1M Na2SO4 electrolyte. The power density and energy density at the current density of 1[Formula: see text]mA [Formula: see text] were determined as 1458.33[Formula: see text]W [Formula: see text] and 91.14[Formula: see text]Wh[Formula: see text][Formula: see text], respectively. Hence, NiO/ZnO nanocomposites could be reckoned to be a promising electrode material for supercapacitor while comparing to ZnO-based electrode material.

scholarly journals Lanthanum Doped Strontium Titanate Nanomaterial for Photocatalytic and Supercapacitor Applications

2020 ◽  
Vol 32 (8) ◽  
pp. 2013-2020 ◽  
Author(s):  
V.V. Deshmukh ◽  
H.P. Nagaswarupa ◽  
C.R. Ravikumar ◽  
M.R. Anil Kumar ◽  
T.R. Shashi Shekhar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Malachite Green ◽  
Strontium Titanate ◽  
Uv Light ◽  
Sol Gel ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Charge Discharge

We report the synthesis of lanthanum doped strontium titanate (Sr1-xLaxTiO3,x=0.1) by sol-gel method. The physical properties of the as-synthesized sample were systematically studied through X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDAX). Diffraction peaks in XRD supported the cubic formation of perovskite-type crystal structure. The image analysis of nanomaterial by SEM and TEM techniques disclosed aggregates of nanoparticles with grain size about 20 nm. The study by UV-DRS exposed the band energy gaps (Eg) of 3.4 eV for strontium titanate nanoparticles, respectively. The degradation studies for three days were carried out for three dyes. Malachite green and rhodamine blue, strontium titanate nanoparticles showed utmost photocatalytic activity for rhodamine blue under UV light irradiation (from 0 to 80 min) as compared to malachite green. Properties of electrochemistry were looked into by cyclic voltammetry and galvanostatic charge/discharge in 1M KCl electrolyte. The Sr0.9La0.1TiO3 electrode displayed maximal specific capacitance of 306.74 F g-1 at current 1mA from galvanostatic charge-discharge curve. The rare earth doped perovskite Sr0.9La0.1TiO3 nanomaterial exhibited increased surface area with superior supercapacitance property.

scholarly journals Nanofiber NiMoO4/g-C3N4 Composite Electrode Materials for Redox Supercapacitor Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 392 ◽  
Author(s):  
Kannadasan Thiagarajan ◽  
Thirugnanam Bavani ◽  
Prabhakarn Arunachalam ◽  
Seung Jun Lee ◽  
Jayaraman Theerthagiri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrode Material ◽  
Composite Electrode ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Galvanostatic Charge ◽  
Transmission Electron ◽  
Cd Studies ◽  
Supercapacitor Applications ◽  
Charge Discharge

NiMoO4/g-C3N4 was fabricated by a hydrothermal method and used as an electrode material in a supercapacitor. The samples were characterized by XRD, FTIR, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to study the physical and structural properties of the as-prepared NiMoO4/g-C3N4 material. The electrochemical responses of pristine NiMoO4 and the NiMoO4/g-C3N4 nanocomposite material were investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). From the CD studies, the NiMoO4/g-C3N4 nanocomposite revealed a higher maximum specific capacitance (510 Fg−1) in comparison to pristine NiMoO4 (203 Fg−1). In addition, the NiMoO4/g-C3N4 composite electrode material exhibited high stability, which maintained up to 91.8% capacity even after 2000 charge-discharge cycles. Finally, NiMoO4/g-C3N4 was found to exhibit an energy density value of 11.3 Whkg−1. These findings clearly suggested that NiMoO4/g-C3N4 could be a suitable electrode material for electrochemical capacitors.

Preparation and Electrochemical Properties of LaMnO3 Powder as a Supercapacitor Electrode Material

2017 ◽  
Vol 727 ◽  
pp. 698-704 ◽  
Author(s):  
Xian Wei Wang ◽  
Xiao Er Wang ◽  
Hui Chao Zhang ◽  
Qian Qian Zhu ◽  
Dong Li Zheng ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Electrode Material ◽  
Raw Materials ◽  
Sol Gel ◽  
Galvanostatic Charge ◽  
Supercapacitor Electrode ◽  
Lanthanum Manganate ◽  
Pure Phase ◽  
Charge Discharge

The structural and electrochemical properties of lanthanum manganate (LaMnO3) powder prepared by the sol-gel method are researched in this article. The powder calcined at 600 °C showed amorphous, and the powder calcined at 700-800 °C showed the pure phase of the LaMnO3. The grains with the size of about 80-120 nm were agglomerating together. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical properties in alkaline environment. The electrochemical properties calcined at 700 °C showed a specific capacitance of 73 F/g at the current density of 0.5 A/g. The raw materials for preparing the LaMnO3 powder are cheap, and the operation method is simple.

scholarly journals Bi1−xEuxFeO3 Powders: Synthesis, Characterization, Magnetic and Photoluminescence Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1465 ◽  
Author(s):  
Vasile-Adrian Surdu ◽  
Roxana Doina Trușcă ◽  
Bogdan Ștefan Vasile ◽  
Ovidiu Cristian Oprea ◽  
Eugenia Tanasă ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bismuth Ferrite ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Weak Ferromagnetism ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
Gel Technique ◽  
Comparative Results

Europium substituted bismuth ferrite powders were synthesized by the sol-gel technique. The precursor xerogel was characterized by thermal analysis. Bi1−xEuxFeO3 (x = 0–0.20) powders obtained after thermal treatment of the xerogel at 600 °C for 30 min were investigated by X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, and Mössbauer spectroscopy. Magnetic behavior at room temperature was tested using vibrating sample magnetometry. The comparative results showed that europium has a beneficial effect on the stabilization of the perovskite structure and induced a weak ferromagnetism. The particle size decreases after the introduction of Eu3+ from 167 nm for x = 0 to 51 nm for x = 0.20. Photoluminescence spectroscopy showed the enhancement of the characteristic emission peaks intensity with the increase of Eu3+ concentration.

Optical, Thermal and Dielectric Studies of Silver-Silica Nanoparticles Synthesized via Sol-Gel Technique

2016 ◽  
Vol 846 ◽  
pp. 318-325
Author(s):  
Taifunisyam Taib ◽  
Souad A. Mohamad ◽  
Mohd Rafie bin Johan ◽  
Wan Jefrey Basiron ◽  
Chin Kim Ming ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Visible Region ◽  
Dielectric Studies ◽  
Silica Nanocomposites ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Mean Size ◽  
Gel Technique ◽  
Thermal Stability Of

Silver-silica nanocomposites (Ag-SiO2NCs) with various compositions were synthesized through sol-gel technique. The morphology, optical and thermal stability of the nanocomposite were investigated and was compared with pure sol-gel to determine the effects of the nanoparticles. Transmission electron microscopy (TEM) confirmed that SiO2 was encapsulated Ag with mean size of 30 nm. Uv-vis spectroscopy shows that the surface plasmon resonance (SPR) peak show Ag-SiO2 NCs were greatly reduce due to the SiO2 particles. The permittivity and refractive index were decreased as the composition of Ag was increased at composition of 60% silver. The real permittivity is negative along the visible region. The trend stability of Ag-SiO2NCs were increased with the increased amount of silver.

Transmission Electron Microscopy of Pzt Thin-Films Prepared by A Sol-Gel Technique

1993 ◽  
Vol 310 ◽  
Author(s):  
Supapan Seraphin ◽  
Dan Zhou ◽  
G. Teowee ◽  
J.M. Boulton ◽  
D.R. Uhlmann
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lead Zirconate Titanate ◽  
Sol Gel ◽  
Chemical Compositions ◽  
Pzt Thin Films ◽  
Transmission Electron ◽  
Average Grain Size ◽  
Gel Technique

AbstractThe microstructure of lead zirconate titanate (PZT) thin films prepared by a sol-gel technique was investigated using transmission electron microscopy (TEM) and transmission electron diffraction. We investigated the microstructure of three sets of thin films with different chemical compositions: PZT 53/47 films with no excess PbO; with excess PbO; and PZT 65/35 with no excess PbO. All samples were fired for 30 minutes at temperatures ranging from 400C to 700C. Incorporation of excess PbO in the 53/47 film fired at 450C resulted in polycrystalline perovskite grains with an average grain size of less than 0.1 μm. Grain boundaries are decorated by 5-10 nm diameter precipitates possibly caused by the segregation of remnant pyrochlore or excess PbO. The films have high values of dielectric constant (up to 2500) when fired at 700C. PZT 65/35 fired at 700C consists of two distinct phases: a fine-grained matrix of pyrochlore, and 10-μm diameter rosettes of perovskite. The correlations between the compositions, the microstructure of the films, and their processing conditions on the one hand, and ferroelectric properties on the other are discussed.

Evaluation of Novel Nanophase Ce0.8Sr0.2Fe0.9Ir0.1O3-δ as Cathode Material for Low Temperature SOFC

2016 ◽  
Vol 44 ◽  
pp. 35-50 ◽  
Author(s):  
Chima Benjamin Njoku ◽  
Patrick Gathura Ndungu
Keyword(s):  
Electron Microscopy ◽  
Solid Oxide Fuel Cells ◽  
Cathode Material ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Low Temperature Sofc ◽  
Gel Technique ◽  
Perovskite Type ◽  
A Current

In this study, Ce0.8Sr0.2Fe0.9Ir0.1O3-δ (CSFI) perovskite type material was prepared by sol-gel technique, characterised, and then tested as a cathode material for solid oxide fuel cells operating between 300 – 500 °C. The materials were studied using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The morphology was examined using scanning electron microscopy and high resolution transmission electron microscopy. Samples showed changes in the overall structure and defect chemistry with an increase in calcination temperature. When tested as cathode materials, the material calcined at 1000 °C had the greatest performance at a test temperature of 500 °C, with a current density of 774.47 mA/cm2, a power density of 483.07 mW/cm2 and an area specific resistance (ASR) of 0.342 Ω/cm2.

Hydrothermal Synthesis and Electrochemical Study of VOx/CNTs Composites

2009 ◽  
Vol 79-82 ◽  
pp. 1787-1790
Author(s):  
Quan Yao Zhu ◽  
Si Ping Hu ◽  
Fei Wu ◽  
Wen Chen
Keyword(s):  
Carbon Nanotubes ◽  
Hydrothermal Synthesis ◽  
Sol Gel ◽  
Vanadium Oxides ◽  
Discharge Process ◽  
Galvanostatic Charge ◽  
Electrochemical Behaviors ◽  
Morphology And Structure ◽  
Ft Ir ◽  
Charge Discharge

Vanadium oxide/carbon nanotubes (VOx/CNTs) composites were prepared by sol-gel hydrothermal synthesis. The composites were characterized in terms of surface morphology and structure using SEM, TEM, XRD, FT-IR, respectively. The electrochemical behaviors of the composites were investigated by means of galvanostatic charge-discharge cycling. The result shows that the vanadium oxides nanotubes and carbon nanotubes contacted each other and the composites have great cycleability as well as capacity characteristics which arrived at 303.5 mAh/g in the first discharge process and 200.4 mAh/g after 50th discharge cycles.

scholarly journals Synthesis of Carbon Nanofibers with Maghemite via a Modified Sol-Gel Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Nicolás Díaz Silva ◽  
Benjamín Valdez Salas ◽  
Nicola Nedev ◽  
Mario Curiel Alvarez ◽  
José M. Bastidas Rull ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanofibers ◽  
Sol Gel ◽  
Energy Dispersive ◽  
Synthesis Process ◽  
Xps Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Technique ◽  
Microscopy Images

Carbon nanohybrid material (CNF/γ-Fe2O3) was obtained via a modified sol-gel technique consisting of two steps: functionalization of carbon nanofibers (CNF) in H2SO4/HNO3 followed by synthesis using Fe(NO3)3∙9H2O. As a result, the iron content of the CNF/γ-Fe2O3 was increased by more than twice from about 40% to about 87% mass percent, compared to the pristine CNF and oxidized CNF specimens, as proved by energy dispersive X-ray fluorescence. Scanning electron microscopy images exhibited “cumulus” on the CNF/γ-Fe2O3 specimen surface, which showed the highest iron mass percentage, proved by energy dispersive X-ray spectroscopy. Transmission electron microscopy images confirmed attachment of γ-Fe2O3 cumulus to the inner and outer surfaces of the CNF walls after synthesis. The characteristic peaks of Fe 2p3/2 and Fe 2p1/2 appeared in the XPS spectra obtained on CNF/γ-Fe2O3. In addition, X-ray diffraction (XRD) results indicated formation of γ-Fe2O3 during the synthesis process. The Raman spectrum of the CNF/γ-Fe2O3 sample displays peaks with positions close to characteristic peaks of highly crystalline and monodisperse maghemite nanocrystallites. The synthesis of CNF/γ-Fe2O3 leads to an increase in the hydrophilicity of CNF and magnetic properties at room temperature.

Nanostructured red-emitting MgGa2O4:Eu3+ phosphors

2004 ◽  
Vol 19 (5) ◽  
pp. 1504-1508 ◽  
Author(s):  
Bin-Siang Tsai ◽  
Yen-Hwei Chang ◽  
Yu-Chung Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sol Gel ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Gel Technique ◽  
Red Luminescence ◽  
20 Nm

Nano-grained phosphors of Eu3+-doped MgGa2O4 crystallites were prepared by sol-gel technique. The characterization and optical properties of luminescent MgGa2O4:Eu3+ powders have been investigated. The dried sol-gel powders were calcined in air at different temperature from 600 to 1000 °C for 5 h. The x-ray diffraction profiles showed that the MgGa2O4:Eu3+ powders began to crystallize around 600 °C and formed stable MgGa2O4 phase in the temperature range of 600–900 °C. The transmission electron microscopy morphology observations revealed that the fired powders exhibit small grain size less than 20 nm. In the PL studies, under ultraviolet (394 nm) excitation, the calcined powders emitted bright red luminescence (615 nm, 5D0→7F2), and the powders fired at 900 °C were found to have the maximum photoluminescence intensity. The quenching concentration of Eu3+ in MgGa2O4 crystallites was also indicated to be about 5∼6 mol%.

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