Synthesis of Nano-MnO2/CNTs Composite and Electrochemical Properties as Electrode Material for Supercapacitor

2012 ◽  
Vol 512-515 ◽  
pp. 1005-1008 ◽  
Author(s):  
Jian Wang ◽  
Jin Hai Liu ◽  
Xue Bo Zhao ◽  
Guo Lu Li ◽  
Bing Qing Wei
Keyword(s):  
Carbon Nanotube ◽  
Specific Capacitance ◽  
Manganese Oxides ◽  
Room Temperature ◽  
Aqueous Alcohol ◽  
Test Results ◽  
Multiwalled Carbon ◽  
Scan Rate ◽  
Swnt Film ◽  
Better Than

The manganese oxides (MnO2) with nanostructures was fabricated with non-aqueous alcohol and aqueous solution of potassium permanganate (KMnO4) at room temperature. The test results show that the nano-MnO2 well coated on the surface of carbon nanotube (CNT), while the specific capacitance of the composites with MnO2 deposited on singlewall carbon nanotube (SWNT) was better than coated on multiwalled carbon nanotube (MWNT). The specific capacitance of MnO2 coated on SWNT film can reach 769F/g at scan rate of 5mv/s in the first cycle.

scholarly journals Synthesis of Metal Oxide Decorated Polycarboxyphenyl Polymer-Grafted Multiwalled Carbon Nanotube Composites by a Chemical Grafting Approach for Supercapacitor Application

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Do-Yeon Kang ◽  
Pashupati Pokharel ◽  
Yeong-Seok Kim ◽  
Sunwoong Choi ◽  
Seong-Ho Choi
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Metal Oxide ◽  
Specific Capacitance ◽  
Metal Oxide Nanoparticles ◽  
Morphological Characteristics ◽  
Multiwalled Carbon Nanotube ◽  
Oxide Nanoparticles ◽  
Multiwalled Carbon ◽  
Scan Rate

We present grafting of polycarboxyphenyl polymer on the surface of multiwalled carbon nanotube (MWCNT) via a free radical polymerization and subsequent anchoring of the metal oxide nanoparticles for the evaluation of their potential applicability to supercapacitor electrodes. Here, metal oxide nanoparticles, Fe3O4and Sm2O3, were created after the oxidation of metal precursors Sm(NO3)3and FeCl2, respectively, and attached on the surface of polycarboxyphenyl-grafted MWCNT (P-CNT) in aqueous medium. This approach shows a potential for enhancing the dispersion of Fe3O4and Sm2O3nanoparticles on the wall of P-CNT. The structure and morphological characteristics of the purified MWCNT, P-CNT, and metal oxide-anchored polycarboxyphenyl-grafted MWCNT (MP-CNT) nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The electrochemical performance of the purified MWCNT electrode, P-CNT electrode, and MP-CNT electrodes was tested by cyclic voltammetry (CV) and galvanostatic charge discharge in a 1.0 M H2SO4aqueous electrolyte. The results showed that the specific capacitance of the purified MWCNT was 45.3 F/g at the scan rate of 5 mV/s and increased to 54.1 F/g after the modification with polycarboxyphenyl polymer. Further modification of P-CNT with Sm2O3and Fe3O4improved the specific capacitance of 65.84 F/g and 173.38 F/g, respectively, at the same scan rate.

Buckypaper/DYAD/Buckypaper and Buckypaper/DYAD/ (polyaniline/multiwalled carbon nanotube) composite sensors: Preparation and damping properties characterization

2017 ◽  
Vol 52 (11) ◽  
pp. 1457-1464
Author(s):  
Weiwei Lin ◽  
Yonatan Rotenberg ◽  
Hadi Fekrmandi ◽  
Cesar Levy
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Damping Ratio ◽  
Multiwalled Carbon Nanotube ◽  
Layer By Layer ◽  
Test Results ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Nanotube Composites ◽  
Matrix Free

Buckypaper/DYAD/Buckypaper and Buckypaper/DYAD/(polyaniline/multiwalled carbon nanotube) composites films were made by frit compression method and layer-by-layer attachment method. Transmission electron microscopy and scanning electron microscopy were used to study the morphology properties of polyaniline/multiwalled carbon nanotube and the results showed that carbon nanotubes were well dispersed in the polymer matrix. Free vibration test results showed that the double-sided attachment of the sensor had higher damping ratio values than single-sided attachment. Also, damping ratios were higher when the composite sensor was placed at the beam's clamped end. Furthermore, the Buckypaper/DYAD/(polyaniline/multiwalled carbon nanotube) combination exhibited higher damping ratios than the other cases tested. Thus, these samples have the potential of being simultaneously strain sensors and dampers.

Multiwalled Carbon Nanotube Oxygen Sensor: Enhanced Oxygen Sensitivity at Room Temperature and Mechanism of Sensing

2015 ◽  
Vol 7 (43) ◽  
pp. 23857-23865 ◽  
Author(s):  
Krishnamoorthy Rajavel ◽  
Murugan Lalitha ◽  
Joghee Kullan Radhakrishnan ◽  
Lakshmipathi Senthilkumar ◽  
Ramasamy Thangavelu Rajendra Kumar
Keyword(s):  
Carbon Nanotube ◽  
Room Temperature ◽  
Oxygen Sensor ◽  
Multiwalled Carbon Nanotube ◽  
Oxygen Sensitivity ◽  
Multiwalled Carbon

scholarly journals Research on Fatigue Properties of Typical Welded Joints of DH36 Steel at −60 °C

2020 ◽  
Vol 10 (11) ◽  
pp. 3742
Author(s):  
Weidong Zhao ◽  
Guoqing Feng ◽  
Wenchao Liu ◽  
Huilong Ren
Keyword(s):  
Stress Concentration ◽  
Welded Joints ◽  
Room Temperature ◽  
Polar Region ◽  
Hot Spot ◽  
Fatigue Properties ◽  
Test Results ◽  
Hot Spot Stress ◽  
Confidence Levels ◽  
Better Than

As the development of the polar region continues to increase, the fatigue properties of structures at low temperature are increasingly receiving researcher attention. This study aimed to investigate the fatigue properties of T-welded and cruciform welded joints at −60 °C. Logarithmic S–N curves based on the hot-spot stress of the T-welded and cruciform welded joints at 50% and 95% confidence levels were obtained at −60 °C. The test results showed that the fatigue properties of T-welded joints were almost 2–7% better than those of the cruciform welded joints at −60 °C. Factors that affected the fatigue properties of welded joints, such as the stress concentration factor, microstructure, Vickers hardness profiles, and fractography, were also studied and the test results showed that the fatigue properties of cruciform welded joints at −60 °C were 57.215% better than at room temperature.

Process Integration of Composite High-k Tunneling Dielectric for Nanocrystal Based Carbon Nanotube Memory

2006 ◽  
Vol 961 ◽  
Author(s):  
Udayan Ganguly ◽  
Tuo-Hung Hou ◽  
Edwin Chihchuan Kan
Keyword(s):  
Carbon Nanotube ◽  
Room Temperature ◽  
Process Integration ◽  
Dielectric Film ◽  
Defect Density ◽  
Vertical Scaling ◽  
Tunnel Barrier ◽  
High K ◽  
Better Than ◽  
Room Temperature Operation

ABSTRACTRecently, metal nanocrystal based carbon nanotube memory has been demonstrated with sub-5V low bias programming, single electron sensitivity but poor room temperature retention. The process integration of an ultra-thin tunnel dielectric is essential for lateral, vertical scaling and reliable room temperature operation. Low defect density and conformal deposition on the nanotube are required to enhance the performance as a tunnel barrier. Additionally, Au contamination in the CNT decreases the on/off current ratio in the CNTFETs by substantially increasing the off current. Consequently, the dielectric should function as a good diffusion barrier for Au in the nanocrystals. We have explored composite tunneling dielectric film with SiO2 seed layer for conformal high-k deposition to demonstrate minimal Au contamination and improved retention. Room temperature retention of better than three days has been observed.

Vertically Aligned Carbon Nanotube Arrays for Room Temperature Gas Sensors

2007 ◽  
Vol 1057 ◽  
Author(s):  
Suresh Rajaputra ◽  
Raghu Mangu ◽  
Ning Ma ◽  
Patricia Clore ◽  
Dali Qian ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Carbon Layer ◽  
Anodized Aluminum ◽  
Multiwalled Carbon ◽  
Anodized Aluminum Oxide ◽  
Cnt Arrays ◽  
Vertically Aligned ◽  
P Type

ABSTRACTVertically aligned multiwalled carbon nanotube (CNT) arrays were fabricated in anodized aluminum oxide (AAO) templates without the use of a catalyst, using xylene pyrolysis. The CNT arrays in AAO template were integrated into a resistive sensor design. The sensors were found to be highly responsive to NH3 and NO2 with steady state sensitivities of 5% and 10% for 100ppm of NH3 and NO2 respectively, at room temperature. Results were interpreted in terms of the CNTs acting as p-type semiconductors. A study was undertaken to elucidate the dependence of sensitivity on the thickness of the conducting amorphous carbon layers on top and bottom. Recovery of the MWNT gas sensor was studied for different types of desorption techniques. The thickness of the amorphous carbon layer (sheet resistance) was found to be critical in determining the sensor response.

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