scholarly journals A Comparison of the Electrochemical Behavior of Carbon Aerogels and Activated Carbon Fiber Cloths

1996 ◽  
Vol 431 ◽  
Author(s):  
T. D. Tran ◽  
C. T. Alviso ◽  
S. S. Hulsey ◽  
J. K. Nielsen ◽  
R. W. Pekala

AbstractThe electrochemical capacitative behavior of carbon aerogels and selected commercial carbon fiber cloths was studied in 5M potassium hydroxide, 3M sulfuric acid, and 0.5M tetraethylammonium tetrafluoroborate/propylene carbonate electrolytes. The resorcinolformaldehyde based carbon aerogels with a range of density (0.2–0.85 g/cc) have open-cell structures with ultrafine pore sizes (∼5–50 nm), high surface area (400–700 m2/g), and a solid matrix composed of interconnected particles or fibers with characteristic diameters of 10 nm. The commercial fiber cloths in the density range 0.2–0.4g/cc have high surface areas (1000–2500 m2/g). The volumetric capacitances of high-density aerogels are shown to be comparable to or exceeding those obtained from activated carbon fibers. The electrochemical behavior of these types of materials in various electrolytes is compared and related to their physical properties.

2011 ◽  
Vol 347-353 ◽  
pp. 3641-3644
Author(s):  
Hui Xing Huang ◽  
Shao Bin Huang ◽  
Shui Xia Chen

Activated carbon Fiber supported PtRu hollow nanospheres have been prepared by a replacement reation in a homogeneous solution with cobalt nanoparticles as sacrificial templates. The morphology, elemental composition, structure and electrocatalytic properties of the PtRu hollow nanospheres have been investigated by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and typical electrochemical methods, respectively. The results indicate that the ACF supported PtRu hollow nanospheres show a high activity and stability for electrocatalytic oxidation of methanol as compared to co-reduced solid PtRu nanoparticles. The reasons of the high electrocatalytic activity due to the high surface area resulted from the hollow nanosphere structure with porous shell.


Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 367-374 ◽  
Author(s):  
Yuxiang Huang ◽  
Wenji Yu ◽  
Guangjie Zhao

AbstractA novel way to prepare mesoporous activated carbon fibers (ACFs-P) has been developed, while the ACFs-P with high surface area were obtained from liquefied wood by combining polyvinyl butyral (PVB) blending and steam activation. The porosity properties of the new material was investigated by N2adsorption and the Brunauer–Emmett–Teller (BET) surface area was found to be 2710 m2g−1and a pore volume of 1.540 cm3g−1, of which 58.2% was mesoporous with diameters between 3 and 6 nm. ACFs-P had a higher methylene blue (MB) adsorption capacity (962 mg/g) than the PVB-added carbon fibers (CFs-P) and ACFs-P without PVB (ACFs-C). Flexible all-carbon yarn supercapacitors can be produced from ACFs-P as powder or fiber. The fiber approach led to yarn supercapacitors with a less favorable electrochemical performance than the powder based production owing to the poor strength of the fibers. A 10 cm long yarn supercapacitor from the powdered ACFs exhibited a high specific length capacitance of 43 mF cm−1at 2 mV s−1. Yarn supercapacitors showed an excellent mechanical flexibility and its capacitor properties were not diminished after bending or crumpling.


1995 ◽  
Vol 393 ◽  
Author(s):  
R.W. Pekala ◽  
C.T. Alviso ◽  
J.K. Nielsen ◽  
T.D. Tran ◽  
G.A.M. Reynolds ◽  
...  

ABSTRACTThe ability to tailor the structure and properties of porous carbons has led to their increased use as electrodes in energy storage devices. Our research focuses on the synthesis and characterization of carbon aerogels for use in electrochemical double layer capacitors. Carbon aerogels are formed from the sol-gel polymerization of (1) resorcinol-formaldehyde or (2) phenolic-furfural, followed by supercritical drying from carbon dioxide, and subsequent pyrolysis in an inert atmosphere. These materials can be produced as monoliths, composites, thin films, powders, or microspheres. In all cases, the aerogels have an open-cell structure with an ultrafine pore size (<100 nm), high surface area (400-1100 m2/g), and a solid matrix composed of interconnected particles, fibers, or platelets with characteristic dimensions of 10 nm. This paper examines the effects of the carbon precursor and processing conditions on electrochemical performance in aqueous and organic electrolytes.


2021 ◽  
Author(s):  
Ensiyeh Taheri ◽  
Mohammad Mehdi Amin ◽  
Ali Fatehizadeh ◽  
Eder C. Lima

Abstract In the present study, zinc chloride followed by acid treating was employed for fabrication activated carbon with a high surface area from pomegranate husk (APHAC) for 2,4-dichlorophenol (2,4-DCP) adsorption. The APHAC was a well-developed pore and exhibiting specific surface areas of 1576 m2/g. Based on the XRD analysis, the diffraction peaks between 15 ° and 35 ° corresponded to amorphous carbon, and the pHpzc values of APHAC was 6.15 ± 0.15. According to batch experiments, the optimum adsorption condition of 2,4-DCP was pH of 3, contact time 60 min, and APHAC dose of 1.75. The absorption capacity of 2,4-DCP at the APHAC dose of 0.5 promptly decreased from 259.5 ± 12.9 mg/g at the initial concentration of 150 mg/L to 74.5 ± 3.7 mg/g dose of 2 g/L. With increasing temperature from 10°C to 50°C, the adsorption efficiency declined from 99.8 ± 0.5% to 75.6 ± 1.89%. The isotherm and kinetic of 2,4-DCP by APHAC revealed that Freundlich and Elovich satisfactorily fitted with experimental data.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2829
Author(s):  
Zhongzhi Yang ◽  
Roland Gleisner ◽  
Doreen H. Mann ◽  
Junming Xu ◽  
Jianchun Jiang ◽  
...  

Activated carbon (AC) with a very high surface area of over 2000 m2/g was produced from low sulfur acid hydrotropic lignin (AHL) from poplar wood using H3PO4 at a moderate temperature of 450 °C (AHL-AC6). ACs with similar surface areas were also obtained under the same activation condition from commercial hardwood alkali lignin and lignosulfonate. Initial evaluation of AC performance was carried out using nitrogen adsorption-desorption and dye adsorption. AHL-AC6 exhibited the best specific surface area and dye adsorption performance. Furthermore, the adsorption results of congo red (CR) and methylene blue (MB) showed AHL-AC6 had greater adsorption capacity than those reported in literature. The dye adsorption data fit to the Langmuir model well. The fitting parameter suggests the adsorption is nearly strong and near irreversible, especially for MB. The present study for the first time provided a procedure for producing AC from lignin with Brunauer–Emmett–Teller (BET) surface area >2000 m2/g using low cost and low environmental impact H3PO4 at moderate temperatures.


2001 ◽  
Vol 11 (PR3) ◽  
pp. Pr3-279-Pr3-286
Author(s):  
X. Dabou ◽  
P. Samaras ◽  
G. P. Sakellaropoulos

2019 ◽  
Author(s):  
Chem Int

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.


Sign in / Sign up

Export Citation Format

Share Document