• 한국전기전자재료학회논문지
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• 제23권10호
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• pp.814-819
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• 2010

Porous carbon electrodes with wooden materials are manufactured by molding carbonized wood powder. Electrical properties of the interface for electrolyte and porous carbon electrode are investigated from viewpoint of NaCl electrolyte concentration, capacitance and complex impedance. Density of porous carbon materials is 0.47~0.61 g/$cm^3$. NaCl electrolytic absorptance of the porous carbon materials is 5~30%. As the electrolyte concentration increased, capacitance is increased and electric resistance is decrease with electric double layer effect of the interface. The electric current of the porous carbon electrode compared in the copper and the high density carbon electrode was improved on a large scale, due to a increase in surface area. The circuit current increased as the distance between of the porous carbon electrode and the zinc electrode decreased, due to increase in electric field. Experimental results indicated that the current properties of galvanic cell could be improved by using porous carbon electrode.

• Journal of Electrochemical Science and Technology
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• 제15권1호
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• pp.111-131
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• 2024

Lignin-derived porous carbon has been identified as a versatile electrode material for supercapacitors (SCs) in energy storage systems (ESSs) owing to their intrinsic advantages including good electrical conductivity, low cost, high thermal and chemical stability, and high porosity, which stem from high surface, appropriate pore distribution, tailored morphologies, heterostructures, and diverse derivates. In this review, to provide a fundamental understanding of the properties of lignin, we first summarize the origin, historical development, and basic physicochemical properties. Next, we describe essential strategies for the preparation of lignin-derived porous carbon electrode materials and then highlight the latest advances in the utilization of lignin-derived porous carbon materials as advanced electrode materials. Finally, we provide some of our own insights into the major challenges and prospective research directions of lignin-derived porous carbon materials for supercapacitors. We believe that this review will provide general guidance for the design of next-generation electrode materials for supercapacitors.

• 한국농공학회논문집
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• 제51권4호
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• pp.21-27
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• 2009

This study was performed to evaluate the physical and mechanical properties of porous concrete using waste activated carbon. Material used were ordinary portland cement, recycled coarse aggregate, waste activated carbon and superplasticizer. The replacement ratios of waste activated carbon were 0,1,2,3,4,5,6,7,8,9, and 10 %. The void ratio was decreased and ultrasonic pulse velocity was increased with increasing the waste activated carbon powder, respectively. The compressive strength and flexural strength of porous concrete using waste activated carbon powder were in the range of 8.21${\sim1}$6.58 MPa and 1.69${\sim1}$3.68 MPa, respectively. The pH degree of porous concrete in 1day and 77days were shown in 12.50${\sim1}$12.63 and 10.21${\sim1}$10.70, respectively. Accordingly, waste activated carbon can be used for porous concrete material.

• Carbon letters
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• 제8권1호
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• pp.17-24
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• 2007

Microporous carbons with narrow pore size distribution have been successfully synthesized by using hydrolyzed and calcined silica as templates and phenol formaldehyde (pf) resin as carbon precursor. Phenol formaldehyde-silica micro composites were prepared by solution route. Subsesequently, silica templates were removed by HF leaching. Resulting carbons were steam activated. The porous carbons were characterized by nitrogen adsorption-desorption isotherm, SEM, FTIR analysis, iodine adsorption, thermogravimetry analysis, etc. Adsorption isotherms show that the porous carbon prepared from calcined silica as templates are microporous with 88% pores of size <2 nm porosity and are of type I isotherm, while porous carbon prepared by using hydrolyzed silica are microporous with 89% microporosity, shows hysteresis loop at high relative pressure indicating the presence of some mesoporosity in samples. The microporosity in porous carbon materials has a bearing on the nature of silica templates used for pore formation.

• 한국세라믹학회지
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• 제44권7호
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• pp.381-386
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• 2007

A porous reaction bonded silicon carbide (RBSC) was fabricated by a molten Si infiltration method. The porosity and flexural strength of porous RBSC fabricated in this study were dependent upon the amount of carbon source used in the SiC/carbon preform as well as the amount of Si infiltrated into the SiC/carbon preform. The porosity and flexural strength of porous RBSC were in the range of $20 vo1.{\sim}49 vo1.%$ and $38{\sim}61 MPa$, respectively. With increase of carbon contents and molten Si for infiltration, volume fraction of the pores was gradually decreased, and flexural strength was increased. The porous RBSCs fabricated with the same amount of molten Si show less residual Si around neck with increase of carbon source, as well as a new SiC was formed around neck which resulted in the decreased porosity and improvement of the flexural strength. In addition, decrease of the porosity and increase of the flexural strength were also obtained by increase of the amount of molten Si with the same amount of carbon source. However, it was found that the flexural strength of porous RBSC depends on the porosity rather than the amount of the newly formed SiC in neck phase between SiC particles used as a starting material.

• 한국결정성장학회지
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• 제17권5호
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• pp.196-203
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• 2007

We have studied a method for the preparation of hybrid $carbon/TiO_2$ complexes involving pitch coating, pitch binding and the penetration of titanium n-butoxide(TNB) solution with porous carbon. The photocatalysts were investigated with surface textural properties and SEM morphology, structural crystallinity and elemental identification between porous carbon and $TiO_2$, and dye decomposition performance. For the all $carbon/TiO_2$ complexes prepared by some kinds of different methods, the excellent photocatalytic effect for dye degradation should be attributed to the both effects between photo-decomposition of the supported $TiO_2$ and adsorptivity of the porous carbons.

• 한국산업융합학회 논문집
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• 제9권1호
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• pp.87-91
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• 2006

This research exposes the process of carbonization of solid waste from the city and the method of activated, as well as the process of meso-porous under several test conditions. In addition, it is expected that the active carbon obtained through this process can be used as filter for air and sewage treatment, and can absorb dioxin(as almost 60-80% of meso-porous and porous properties area) unlike the existing active carbon.

• KSBB Journal
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• 제28권4호
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• pp.225-229
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• 2013

Bovine Carbonic anhydrase (BCA) was immobilized on a submicro-porous membrane through covalent immobilization. The immobilization was conducted on the porous membrane surface with the treatment of polyethyleneimine, glutaraldehyde, and the anhydrase, in sequence. The immobilization was confirmed using X-ray photon spectrometer. The pH values of carbon-dioxide saturated solution with buffer were monitored with respect to time to calculate the catalytic activities of hydration of carbon-dioxide for free and immobilized CA. The catalytic rate constant values for free CA, immobilized CA on polystyrene nanoparticles, and immobilized CA on a porous cellulose acetate membrane were 0.79, 0.67, and 0.56 $s^{-1}$, respectively. Reusability was studied up to 10 cycles of $CO_2$ sequestration. The activity for the CA immobilized on the membrane was kept to 95% after 10 cycles, and comparable to the CA on the nanoparticles. The stabilities for heat and storage were also investigated for the three cases. The results suggested that the CA immobilized the membrane had the least loss rate of the activity compared to the others. From this study, the porous membrane was feasible as a carrier for the CA immobilization in hydration and sequestration of carbon-dioxide.

• Carbon letters
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• 제10권3호
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• pp.217-220
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• 2009

In this study, porous electrospun carbon fibers were prepared by electrospinning with PAN and $MgCl_2$, as a MgO precursor. MgO was selected as a substrate because of its chemical and thermal stability, no reaction with carbon, and ease of removal after carbonization by dissolving out in acidic solutions. $MgCl_2$ was mixed with polyacrylonitrile (PAN) solution as a precursor of MgO with various weight ratios of $MgCl_2$/PAN. The average diameter of porous electrospun carbon fibers increased from 1.3 to 3 ${\mu}m$, as the $MgCl_2$ to PAN weight ratio increased. During the stabilization step, $MgCl_2$ was hydrolyzed to MgOHCl by heat treatment. At elevated temperature of 823 K for carbonization step, MgOHCl was decomposed to MgO. Specific surface area and pore structure of prepared electrospun carbon fibers were decided by weight ratio of $MgCl_2$/PAN. The amount of hydrogen storage increased with increase of specific surface area and micropore volume of prepared electrospun carbon fibers.

• Carbon letters
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• 제9권3호
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• pp.188-194
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• 2008

Porous carbon materials synthesized from various plant derived precursors i.e. seeds of [Castor (Ricinus communis), Soap nut (Sapindus sp.), Cashew-nut (Semecarpus anacardium), Jack fruit (Artocarpus heterophyllus), Safflower (Carthamus tinctorius), Ambadi (Crotolaria juncea), Neem (Azadirachta indica), Bitter Almond (Prunus amygdalus), Sesamum (Sisamum indicum), Date-palm (Phoenix dactylifera),Canola (Brassica napus), Sunflower (Helianthus annulus)] and fibrous materials from [Corn stem- (Zea mays), Rice straw (Oryza sativa), Bamboo (Bombax bambusa) and Coconut fibers (Cocos nucifera)] were screened to make supercapacitor in 5M KOH solution. Carbon material obtained from Jack fruit seeds (92.0 F/g), Rice straw (83.0 F/g), Soap nut seeds (54.0 F/g), Castor seeds (44.34 F/g) and Bamboo (40.0 F/g) gave high capacitance value as compared to others. The magnitude of capacitance value was found to be inversely proportional to the scan rate of measurement. It is suggested that carbon material should possess large surface area and small pore size to get better value of capacitor. Moreover, the structure of carbon materials should be such that majority of pores are in the plane parallel to the plane of electrode and surface is fluffy like cotton ball.