Preparation and characterization of high-surface-area activated carbon fibers from silkworm cocoon waste for congo red adsorption

2015 ◽  
Vol 75 ◽  
pp. 189-200 ◽  
Author(s):  
Jia Li ◽  
Dickon H.L. Ng ◽  
Peng Song ◽  
Chao Kong ◽  
Yi Song ◽  
...  
2005 ◽  
Vol 876 ◽  
Author(s):  
Mark Crocker ◽  
Uschi M. Graham ◽  
Rolando Gonzalez ◽  
Erin Morris ◽  
Gary Jacobs ◽  
...  

AbstractHigh surface area cerium oxide has been prepared using a carbon templating method. Impregnation of a highly mesoporous activated carbon (Darco KB-B) with an aqueous solution of cerium nitrate, followed by carbon burn off, afforded ceria with surface area of up to 148 m2/g. According to thermogravimetric studies, ceria formation proceeds via decomposition of cerium nitrate at ca. 410 K; oxidation of the carbon template commences at the same temperature, being facilitated by the release of NO2 from the Ce compound. Use of activated carbon fibers (ACFs) as template was found to provide a simple route to fibrous cerium oxide. The lower surface areas (3 - 59 m2/g) of the resulting ceria fibers reflect the largely microporous nature of the ACFs; evidently the Ce nitrate solution is unable to penetrate their micropores. Consequently, the surface area of the ceria product is found to increase with increasing mesoporosity of the ACF template. Electron microscopy reveals that the ceria fibers are composed of highly crystalline primary particles of 5-10 nm diameter; further, the fibers display a number of interesting morphological features at the macro- and nano-scales.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1877 ◽  
Author(s):  
Feng-Cheng Chang ◽  
Shih-Hsuan Yen ◽  
Szu-Han Wang

In this study, electrospinning technology, physical activation, and carbonization processing were applied to produce lignosulfonate-based activated carbon fibers. The porous structure of the produced lignosulfonate-based activated carbon fibers primarily contained mesopores and a relatively small amount of micropores. Moreover, insufficient carbonization caused fiber damage during CO2 activation. The weight loss rate and specific surface area increased with increase in carbonization time, and products with carbonization temperatures of 700 °C were of higher quality than those with other temperatures. Moreover, the two-step carbonization process provided fibers with improved quality because of a low weight loss rate, improved processing, and high surface area. Lignosulfonate-based activated carbon fibers can be used as a highly efficient adsorption and filtration material, and further development of its applications would be valuable.


2017 ◽  
Vol 36 (3) ◽  
pp. 44-53
Author(s):  
G. D. Akpen ◽  
M. I. Aho ◽  
N. Baba

Activated carbon was prepared from the pods of Albizia saman for the purpose of converting the waste to wealth. The pods were thoroughly washed with water to remove any dirt, air- dried and cut into sizes of 2-4 cm. The prepared pods were then carbonised in a muffle furnace at temperatures of 4000C, 5000C, 6000C ,7000C and 8000C for 30 minutes. The same procedure was repeated for 60, 90, 120 and 150 minutes respectively. Activation was done using impregnationratios of 1:12, 1:6, 1:4, 1:3, and 1:2 respectively of ZnCl2 to carbonised Albizia saman pods by weight. The activated carbon was then dried in an oven at 1050C before crushing for sieve analysis. The following properties of the produced Albizia saman pod activated carbon (ASPAC) were determined: bulk density, carbon yield, surface area and ash, volatile matter and moisture contents. The highest surface area of 1479.29 m2/g was obtained at the optimum impregnation ratio, carbonization time and temperature of 1:6, 60 minutes and 5000C respectively. It was recommended that activated carbon should be prepared from Albizia saman pod with high potential for adsorption of pollutants given the high surface area obtained.Keywords: Albizia saman pod, activated carbon, carbonization, temperature, surface area


1991 ◽  
Vol 6 (5) ◽  
pp. 1040-1047 ◽  
Author(s):  
K. Kuriyama ◽  
M.S. Dresselhaus

The conductivity and photoconductivity are measured on a high-surface-area disordered carbon material, i.e., activated carbon fibers, to investigate their electronic properties. This material is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000–2000 m2/g. Our preliminary thermopower measurements show that the dominant carriers are holes at room temperature. The x-ray diffraction pattern reveals that the microstructure is amorphous-like with Lc ≃ 10 Å. The intrinsic electrical conductivity, on the order of 20 S/cm at room temperature, increases by a factor of several with increasing temperature in the range 30–290 K. In contrast, the photoconductivity in vacuum decreases with increasing temperature. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The recombination kinetics changes from a monomolecular process at room temperature to a bimolecular process at low temperatures, indicative of an increase in the photocarrier density at low temperatures. The high density of localized states, which limits the motion of carriers and results in a slow recombination process, is responsible for the observed photoconductivity.


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