Active carbon/graphene hydrogel nanocomposites as a symmetric device for supercapacitors

Cinar, Damla
Caliskan, Sinan
Candan, Idris
Activated carbons (ACs) are successfully synthesized from Elaeagnus grain by a simple chemical synthesis methodology and demonstrated as novel, suitable supercapacitor electrode materials for graphene hydrogel (GH)/AC nanocomposites. GH/AC nanocomposites are synthesized via hydrothermal process at temperature of 180 degrees C. The low-temperature thermal exfoliation approach is convenient for mass production of graphene hydrogel (GH) at low cost and it can be used as electrode material for energy storage applications. The GH/AC nanocomposites exhibit better electrochemical performances than the pure GH. Electrochemical performance of the electrodes is studied by cyclic voltammetry, and galvanostatic charge-discharge measurements in 1.0 M H2SO4 solution. A remarkable specific capacitance of 602.36 Fg(1) (based on GH/AC nanocomposites for 0.4 g AC) is obtained at a scan rate of 1 mVs(1) in 1 M H2SO4 solution and 155.78 Fg(1) for GH. The specific capacitance was increased 3.87 times for GH/AC compared to GH electrodes. Moreover, the GH/AC nanocomposites for 0.2 g AC present excellent long cycle life with 99.8% specific capacitance retained after 1000 charge/discharge processes. Herein, ACs prepared from Elaeagnus grain are synthesized GH and AC supercapacitor device for high-performance electrical energy storage devices as a promising substitute to conventional electrode materials for EDLCs.


Surface Modification and Characterization of Multi-Walled Carbon Nanotube
Kanbur, Yasin; Kucukyavuz, Zuhal (Informa UK Limited, 2011-01-01)
Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized by using sulfuric acid and nitric acid. The functionalization was done with two different acid ratio. The functionalized nanotubes were characterized with Fourier Transform Infrared Spectroscopy, X-Ray Photon Spectroscopy, Thermal Gravimetric Analysis, Elemental Analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy. Sulfonation of carbon nanotubes (CN) increased the electrical conductivity of carbon nanotubes ...
Phase transition of chemically synthesized FePt nanoparticles under high pressure
ŞİMŞEK, TELEM; Karci, Ozgur; ÖZCAN, ŞADAN (The Scientific and Technological Research Council of Turkey, 2018-01-01)
We present the results of a study related to phase transformation of chemically synthesized FePt nanoparticles under high pressure from face-centered cubic into face-centered tetragonal structure. As-synthesized nanoparticles are around 4.5 nm and show superparamagnetic behavior at 300 K. After annealing under 60 bar pressure of hydrogen at 400 degrees C for 2 h, nanoparticles exhibit strong ferromagnetic behavior with 5391 Oe coercivity. Results show that high-pressure annealing lowers the decomposition te...
Flexible organic photovoltaics from zinc oxide nanowires grown on transparent and conducting single walled carbon nanotube thin films
Ünalan, Hüsnü Emrah; Kuo, Daniel; Parekh, Bhavin; Amaratunga, Gehan; Chhowalla, Manish (Royal Society of Chemistry (RSC), 2008-01-01)
The fabrication of flexible organic photovoltaics (OPVs) which utilize transparent and conducting single walled carbon nanotube (SWNT) thin films as current collecting electrodes on plastic substrates in zinc oxide nanowire (ZnO NW)/poly(3-hexylthiophene) (P3HT) bulk heterojunction photovoltaic devices is reported. The bulk heterojunctions for exciton dissociation are created by directly growing ZnO nanowires from solution on the SWNT electrodes and spin coating the P3HT polymer. A maximum OPV power convers...
Study of the Influence of Transition Metal Atoms on Electronic and Magnetic Properties of Graphyne Nanotubes Using Density Functional Theory
Alaei, Sholeh; Jalili, Seifollah; Erkoç, Şakir (Informa UK Limited, 2015-01-01)
Density functional theory calculations were used to study the adsorption of three transition metal atoms (Fe, Co, and Ni) on the external surface of two zigzag and two armchair graphyne nanotubes. The most stable position for the adsorption of all three metal atoms on all nanotubes is on the acetylenic ring. The metal atom remains in the plane of the acetylenic ring and makes six bonds with neighboring carbon atoms. Fe and Co complexes are magnetic and show different properties such as metal, semimetal, hal...
Structural properties of carbon nanogears
Tasci, Emre; Malcıoğlu, Osman Barış; Erkoc, Sakir (Informa UK Limited, 2008-01-01)
Structural stabilities of different types of carbon nanogears have been tested against temperature by means of a molecular dynamics procedure. Effects of periodic boundary conditions were also examined. It has been found that although the two types of nanogears (armchair and zigzag CNT yielding) investigated look similar in configuration, when tested against high temperatures, bond breakings and deformations occur at different regions.
Citation Formats
M. ATEŞ et al., “Active carbon/graphene hydrogel nanocomposites as a symmetric device for supercapacitors,” FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES, pp. 427–434, 2016, Accessed: 00, 2020. [Online]. Available: