Facile Synthesis of New Nanocomposite Based on Cobalt Oxide and Carbon Nanotubes with Excellent Electrochemical Capacitive Behavior

2011 ◽  
Vol 399-401 ◽  
pp. 1451-1456 ◽  
Author(s):  
Gang Luo ◽  
Shi Chao Zhang ◽  
Hua Fang
Keyword(s):  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Cobalt Hydroxide ◽  
Potential Range ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Pseudocapacitive Behavior

A new two-step synthesis of composite electrode based on carbon nanotubes (CNTs) and cobalt oxide (Co3O4) by electrophoretic deposition of CNTs on Ni foam followed by electrodeposition of cobalt hydroxide on CNTs electrode and heat treatment to form Co3O4/CNTs composite electrode was developed. The structure and morphology of the electrodes were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their electrochemical performances were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). Experimental results indicated that the nanocomposite electrodes exhibitd excellent pseudocapacitive behavior. In the potential range of 0.1- 0.45 V(vs SCE), the nanocomposite electrode showed a high specific capacitance of 867 F•g-1 in 6 M KOH electrolyte and a capacity retention of 90% after 1000 cycles at a current density of 1 A•g-1.

Temperature Controlled Synthesis of Ce–MnO2 Nanostructure: Promising Electrode Material for Supercapacitor Applications

2020 ◽  
Vol 12 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Rajesh Rajagopal ◽  
Kwang-Sun Ryu
Keyword(s):  
Electrode Material ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Supercapacitor Application ◽  
Structural Details ◽  
Different Temperatures ◽  
Microscope Technique ◽  
Supercapacitor Applications

The objective of this study was to prepare Ce–MnO2 nanostructure composite as an electrode material for supercapacitor application. Ce–MnO2 nanostructure composite was synthesized by facile hydrothermal method at different temperatures. Structural details of pure and Ce–MnO2 nanostructure composite were studied using powder X-ray diffraction technique. The formation of flower like structure and strong interaction with Ce and MnO2 were confirmed by field emission electron microscope technique. Their electrochemical performances were elucidated by using cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy techniques. Nearly rectangular shaped cyclic voltagram was observed for synthesized Ce–MnO2 nanostructure composite electrode, indicating the existence of electric double layer capacitance nature. Ce–MnO2 (130) nanostructure composite exhibited high specific capacitance value of 147.25 F/g at applied current density of 1 A/g in 1 M Li2SO4 aqueous electrolyte. Furthermore, resistive and capacitive behaviors of these electrodes were studied from Nyquist and bode diagrams within frequency range of 10 mHz to 100 kHz.

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.

Chemically Coupled Cobalt Oxide Nanosheets Decorated onto the Surface of Multiwall Carbon Nanotubes for Favorable Oxygen Evolution Reaction

2021 ◽  
Vol 21 (4) ◽  
pp. 2660-2667
Author(s):  
Abdul Qayoom Mugheri ◽  
Aneela Tahira ◽  
Umair Aftab ◽  
Adeel Liaquat Bhatti ◽  
Ramesh Lal ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Material ◽  
Cobalt Oxide ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Electrochemical Impedance ◽  
Multiwall Carbon Nanotubes ◽  
Alkaline Media ◽  
Transfer Resistance ◽  
Multiwall Carbon

Cobalt oxide has been widely investigated among potential transition metal oxides for the electrochemical energy conversion, storage, and water splitting. However, they have inherently low electronic conductivity and high corrosive nature in alkaline media. Herein, we propose a promising and facile approach to improve the conductivity and charge transport of cobalt oxide Co3O4 through chemical coupling with well-dispersed multiwall carbon nanotubes (MWCNTs) during hydrothermal treatment. The morphology of prepared composite material consisting of nanosheets which are anchored on the MWCNTs as confirmed by scanning electron microscopy (SEM). A cubic crystalline system is exhibited by the cobalt oxide as confirmed by the X-ray diffraction study. The Co, O, and C are the only elements present in the composite material. FTIR study has indicated the successful coupling of cobalt oxide with MWCNTs. The chemically coupled cobalt oxide onto the surface of MWCNTs composite is found highly active towards oxygen evolution reaction (OER) with a low onset potential 1.44 V versus RHE, low overpotential 262 mV at 10 mAcm-2 and small Tafel slope 81 mV dec-1. For continuous operation of 40 hours during durability test, no decay in activity was recorded. Electrochemical impedance study further revealed a low charge transfer resistance of 70.64 Ohms for the composite material during the electrochemical reaction and which strongly favored OER kinetics. This work provides a simple, low cost, and smartly designing electrocatalysts via hydrothermal reaction for the catalysis and energy storage applications.

Study on Activated Carbon /Polyaniline Electrode Materials for Supercapacitorsts

2010 ◽  
Vol 97-101 ◽  
pp. 1582-1585 ◽  
Author(s):  
Yan Hong Tian ◽  
Bo Rong Wu ◽  
Ding Wen Mao
Keyword(s):  
Activated Carbon ◽  
Composite Electrode ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Reference Electrode ◽  
Bet Surface Area ◽  
Electrochemical Performances ◽  
Galvanostatic Charge ◽  
Composite Surface ◽  
Pani Composite

Activated carbon (AC)/polyaniline (PANI) composite electrode materials were synthesized in this article. The effect of preparation such as BET surface area and porous size of AC on the electrochemical performances of AC/PANI composite material was investigated. The electrochemical performances of the composite were tested with cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectrometry in 6mol/L KOH solution using Hg/HgO as reference electrode. Composite surface morphology was examined by scanning electron microscope (SEM). The result shows that when the ratio of AC to aniline increases, the conversion of aniline and the capacitance value of composite also increase in keeping the ratio of AC to aniline constant. When AC: aniline : (NH4)2S2O8 =7:1:1, the conversion of aniline up to more than 95% and the capacitance value of electrode materials increased from 239F/g(pure AC) to 409F/g, which is 71.1% higher than pure AC. Pore structure of AC also has great effect on electrochemical performances of electrode material. With the increase of proportion of mesoporous, the electrochemical properties of composite are greatly increased.

Electrochemical performances of cobalt oxide–carbon nanotubes electrodes via different methods as negative material for alkaline rechargeable batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (90) ◽  
pp. 73410-73415 ◽  
Author(s):  
Yanan Xu ◽  
Yanyin Dong ◽  
Xiaofeng Wang ◽  
Yijing Wang ◽  
Lifang Jiao ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Rechargeable Batteries ◽  
Electrochemical Performances ◽  
Negative Materials ◽  
Negative Material ◽  
First Time

Co3O4/CNTs samples are synthesized via different methods and investigated as negative materials for alkaline rechargeable batteries for the first time.

Facile Synthesis of Cobalt Oxide Uniformly Coated on Multi-Wall Carbon Nanotubes for Supercapacitors

2011 ◽  
Vol 306-307 ◽  
pp. 1148-1152 ◽  
Author(s):  
Liang Yu Gong ◽  
Ling Hao Su
Keyword(s):  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Solid Phase ◽  
Synthesis Method ◽  
Electrochemical Performances ◽  
Composite Electrodes ◽  
Phase Synthesis ◽  
Multi Wall Carbon Nanotubes ◽  
Electrochemical Tests ◽  
Transmission Electron

The composite electrodes of cobalt oxide and multi-wall carbon nanotubes (MWCNTs) are prepared by a simple low-temperature solid-phase synthesis method with the assistance of polyethylene glycol and their pseudocapacitive performances are investigated in alkaline solution by cyclic voltammetry and galvanostatic charge/discharge tests, respectively. Transmission electron microscope images show that cobalt oxide is uniformly coated on multi-wall carbon nanotubes and the homogeneous hybrid nanostructure are considered to be responsible for their preferable electrochemical performances. The electrochemical tests further reveal that the composite can deliver a maximum specific capacitance of 217 F/g with a biggest utilization of Co element when the content of MWCNTs increases to 50 wt.%.

Effect of nanomaterials in platinum-decorated carbon nanotube paste-based electrodes for amperometric glucose detection

2008 ◽  
Vol 23 (5) ◽  
pp. 1457-1465 ◽  
Author(s):  
Jining Xie ◽  
Shouyan Wang ◽  
L. Aryasomayajula ◽  
V.K. Varadan
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Electrochemical Impedance ◽  
Glucose Sensing ◽  
Electrochemical Characteristics ◽  
Current Response ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Wide Range

The effect of nanomaterials in platinum-decorated, multiwalled, carbon nanotube-based electrodes for amperometric glucose sensing was investigated by a comparative study with other carbon material-based electrodes such as graphite, glassy carbon, and multiwalled carbon nanotubes. Scanning and transmission electron microscopy and x-ray diffraction were used to investigate their morphologies and crystallinities. Electrochemical impedance spectroscopy was conducted to compare the electrochemical characteristics of these electrodes. The glucose-sensing results from the chronoamperometric measurements indicated that carbon nanotubes improve the linearity of the current response to glucose concentrations over a wide range, and that platinum decoration of the carbon nanotubes produces improved electrochemical performance with a higher sensitivity.

scholarly journals Synthesis of 3D Hollow Structured MnCo2O4/CNTs Nanocomposite and Its Magnetic Properties

2021 ◽  
Author(s):  
Nehad Yousf ◽  
Amir Elzwawy ◽  
Emtinan Ouda ◽  
S. A. Mansour ◽  
El Shazly M. Duraia
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Cobalt Oxide ◽  
Hollow Structure ◽  
X Ray Diffraction ◽  
Post Heat Treatment ◽  
Present Contribution ◽  
Transmission Electron ◽  
Precipitation Procedure ◽  
Co Precipitation

Abstract In the present contribution, the 3D hollow structure of manganese cobalt oxide/carbon nanotubes (MnCo2O4/CNTs) nanocomposite was successfully synthesized through a co-precipitation procedure followed by post-heat treatment. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM). Based on the obtained results, the surface of carbon nanotubes was coated uniformly in radial directions by manganese oxide (MnO2) nanosheets forming a flower-shaped structure. In the next step, cobalt oxide precursor was introduced to form MnCo2O4/CNTs nanocomposite. The XRD data confirms the formation of MnCo2O4/CNTs. The estimated values of the strain and the crystallite size based on the Williamson-Hall (W-H) method are calculated as 5.326×10-4 and 16 nm respectively. The fingerprint area of FTIR suggests the successful incorporation of MnO2 and cobalt oxide onto CNTs’ surfaces. The flower-shaped structure in the nanoscale is verified by the FESEM and TEM devices. Furthermore, the magnetic specifications revealed the paramagnetic with a small ferromagnetic component of the aforementioned MnCo2O4/CNTs nanocomposite.

Homogeneous Growth of Ni(OH)2 Nanoparticle on Carbon Nanotubes for High-Performance Supercapacitor Electrode Material

2017 ◽  
Vol 727 ◽  
pp. 732-737 ◽  
Author(s):  
Fei Fei Sun ◽  
Dong Lin Zhao ◽  
Cheng Li ◽  
Xia Jun Wang ◽  
Ji Xiang Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Performance ◽  
High Performance ◽  
Electrochemical Impedance ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
Chemical Precipitation ◽  
Supercapacitor Electrode ◽  
Supercapacitive Performance ◽  
A Current

A homogeneous Ni (OH)2/ carbon nanotubes (CNTs) nanocomposite with excellent supercapacitive performance has been synthesized via a facile chemical precipitation. The microstructure and morphology of Ni (OH)2/CNTs nanocomposite were investigated by XRD, SEM and TEM. It presented an ideal morphology with the nanosized Ni (OH)2 particles homogeneously growing on the CNTs. The electrochemical performance of the Ni (OH)2/CNTs nanocomposite was test by cyclic voltammetry, galvanostatic charge−discharge and electrochemical impedance spectroscopy techniques. The synthesized Ni (OH)2/CNTs nanocomposite shows superior electrochemical performance, including high capacitance, excellent rate capability and good cycle life. The homogeneous Ni (OH)2/ CNTs nanocomposite exhibited a high specific capacitance of 1741 F g-1 at a current density of 1A g-1 and maintained a good stability after 5000 cycles at 10A g-1`, suggesting that it can be a promising candidate for supercapacitor.

PREPARATION AND CHARACTERIZATION OF A POLY(PYRROLYL METHANE)/MULTIWALLED CARBON NANOTUBES COMPOSITES

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350063
Author(s):  
JINXIAN LIN ◽  
PAN WANG ◽  
YUYING ZHENG
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Electrode System ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Transfer Resistance ◽  
Transmission Electron

A poly(pyrrolyl methane) (Poly[pyrrole-2, 5-diyl(4-methoxybenzylidane)], PPDMOBA)/multiwalled carbon nanotubes (MWNTs) composites are fabricated by in situ chemical polycondensation of pyrrole and 4-methoxybenzaldehyde on MWNTs. The structure, morphology, thermal stability and electrical property of the resulting composites are investigated via fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and a four-probe method. The electrochemical performance of the composites is determined in a three-electrode system using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. FTIR, FESEM and TEM confirm that the composites have been successfully prepared, and PPDMOBA is uniformly dispersed in MWNTs. Electrical conductivity of PPDMOBA/MWNTs composites is 1.39 S cm-1, which is significantly larger than that of pristine PPDMOBA. The specific capacitance and charge transfer resistance of the composites is 56 F g-1 (1 mA cm-2) and 0.3Ω, respectively.

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